Due to its unique properties, amorphous silicon dioxide (
-SiO
) or silica is a key material in many technological fields, such as high-power laser systems, telecommunications, and fiber optics. In ...recent years, major efforts have been made in the development of highly transparent glasses, able to resist ionizing and non-ionizing radiation. However the widespread application of many silica-based technologies, particularly silica optical fibers, is still limited by the radiation-induced formation of point defects, which decrease their durability and transmission efficiency. Although this aspect has been widely investigated, the optical properties of certain defects and the correlation between their formation dynamics and the structure of the pristine glass remains an open issue. For this reason, it is of paramount importance to gain a deeper understanding of the structure-reactivity relationship in
-SiO
for the prediction of the optical properties of a glass based on its manufacturing parameters, and the realization of more efficient devices. To this end, we here report on the state of the most important intrinsic point defects in pure silica, with a particular emphasis on their main spectroscopic features, their atomic structure, and the effects of their presence on the transmission properties of optical fibers.
In January 2020, Novel Coronavirus Disease 2019 (COVID‐19) resulted in a global pandemic, creating uncertainty toward the management of liver transplantation (LT) programs. Lombardy has been the most ...affected region in Italy: the current mortality rate of COVID‐19 patients is 18.3% (10 022 deaths; April 10th) with hospitals in Lombardy having to expand the total number of ICU beds from 724 to 1381 to accommodate infected patients. There has been a drastic decrease in liver donors. From February 23rd until April 10th, 17 LTs were performed in Lombardy. Mean donor age was 49 years (range 18‐74) whereas mean recipient age was 55 (13‐69); mean MELD score was 12 (6‐24). All donors underwent screening for SARS‐CoV‐2 prior to LT. Two patients tested positive after LT, and one patient died for COVID on POD 30. Sixteen patients are alive after an average of 30 days post‐LT (range 3‐46). 10 patients have been discharged. This study has found no specific reason concerning the safety of recipients, to stop LT programs. Several key lessons from our experience are reported. However, due to the complex circumstances which surround the viral outbreak, the cessation or a reduction in LT activity is a pragmatic requirement.
Authors report key lessons and results of 17 liver transplantations performed in 4 liver transplantation centers in Northern
Maintenance immunosuppressive therapy used in kidney transplantation typically involves calcineurin inhibitors, such as tacrolimus or cyclosporine, in combination with mycophenolate or mechanistic ...target of rapamycin (mTORi) with or without corticosteroids. An Italian retrospective multicentre observational study was conducted to investigate the risk-benefit profile of different immunosuppressive regimens. We identified all subjects who underwent kidney transplant between 2009 and 2019, using healthcare claims data. Patients on cyclosporine and tacrolimus-based therapies were matched 1:1 based on propensity score, and effectiveness and safety outcomes were compared using Cox models (HR; 95%CI). Analyses were also conducted comparing mTORi versus mycophenolate among tacrolimus-treated patients. Patients treated with cyclosporine had a higher risk of rejection or graft loss (HR:1.69; 95%CI:1.16-2.46) and a higher incidence of severe infections (1.25;1.00-1.55), but a lower risk of diabetes (0.66;0.47-0.91) compared to those treated with tacrolimus. Among tacrolimus users, mTORi showed non-inferiority to MMF in terms of mortality (1.01;0.68-1.62), reject/graft loss (0.61;0.36-1.04) and severe infections (0.76;0.56-1.03). In a real-life setting, tacrolimus-based immunosuppressive therapy appeared to be superior to cyclosporine in reducing rejection and severe infections, albeit with an associated increased risk of diabetes. The combination of tacrolimus and mTORi may represent a valid alternative to the combination with mycophenolate, although further studies are needed to confirm this finding.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dans ce texte les auteurs explorent les potentialités du recours au dispositif groupal et à l’introduction de la médiation par les images dans la prise en charge de jeunes requérants d’asile. La ...clinique liée aux migrations contemporaines nous confronte à un véritable défi concernant la prise en soin de sujets qui appartiennent à des cultures différentes, parlent des langues diverses et sont porteurs de traumatismes qui se révèlent à la fois singuliers et pluriels. À travers l’exemple d’un groupe à médiation Photolangage® avec des ex-mineurs non accompagnés, l’article décrit comment le modèle psychanalytique de groupe peut être un dispositif original pour la compréhension et le traitement d’une telle clinique.
When present, structural disorder makes it very challenging to characterise the conformational properties of proteins. This is particularly the case of proteins, such as the oncogene protein E7 of ...human papillomavirus type 16, which contain both ordered and disordered domains, and that can populate monomeric and oligomeric states under physiological conditions. Nuclear magnetic resonance (NMR) spectroscopy is emerging as a powerful method to study these complex systems, most notably in combination with molecular dynamics simulations. Here we use NMR chemical shifts and residual dipolar couplings as structural restraints in replica-averaged molecular dynamics simulations to determine the free energy landscape of E7. This landscape reveals a complex interplay between a folded but highly dynamical C-terminal domain and a disordered N-terminal domain that forms transient secondary and tertiary structures, as well as an equilibrium between a high-populated (98%) dimeric state and a low-populated (2%) monomeric state. These results provide compelling evidence of the complex conformational heterogeneity associated with the behaviour and interactions of this disordered protein associated with disease.
The worldwide pandemic outbreak due to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has created unprecedented challenges for public health services. Lombardy, region of the Northern ...Italy, has been the first area in the Western world whose organs and tissues procurement programs have had to face the virus pandemic emergency. We retrospectively collected and analyzed data about cardiovascular tissues (CT) in 2019 and in 2020. We aimed to describe the rapid evolution of SARS-CoV-2 regulation laws for tissue donor’s selection and harvesting from February 2020 until January 2021. As expected the number of CT donors in 2020 was significantly lower than those of 2019 (66 vs. 99,
p
value 0.02). The total number of CT collected from donors have been 254 in 2019 and 206 in 2020 (
p
0.28). Femoral arteries were the most required vascular tissues (55.5% in 2019 and 40% in 2020). Fifty-five and forty-eight pulmonary valves were implanted in 2019 and 2020, respectively. No differences were found for the types of CT requests between the 2 years. The median age of receivers of vascular tissues was 69.6 ± 14.6 years in the 2019 and 63.3 ± 14.9 years in 2020 (
p
< 0.01). The median age of receivers of pulmonary and aortic valves did not differ between the 2 years (9.32 ± 11.49 vs. 8.36 ± 10.66 and 48.67 ± 27.19 vs. 37.14 ± 31.97 respectively). Despite the dramatically reduction of donors, the number of CT collected has not decreased significantly and so far the CT distribution rate is comparable to those of 2019.
The goal of post-transplant immunosuppressive drug therapy is to prevent organ rejection while minimizing drug toxicities. In clinical practice, a multidrug approach is commonly used and involves ...drugs with different mechanisms of action, including calcineurin inhibitors (CNI) (tacrolimus or cyclosporine), antimetabolite (antimet) (mycophenolate or azathioprine), inhibitors of mechanistic target of rapamycin (mTOR) (sirolimus or everolimus), and/or steroids. Although evidence based on several randomized clinical trials is available, the optimal immunosuppressive therapy has not been established and may vary among organ transplant settings. To improve the knowledge on this topic, a multiregional research network to Compare the Effectiveness and Safety of Immunosuppressive drugs in Transplant patients (CESIT) has been created with the financial support of the Italian Medicines Agency. In this article, we describe the development of this network, the framework that was designed to perform observational studies, and we also give an overview of the preliminary results that we have obtained. A multi-database transplant cohort was enrolled using a common data model based on healthcare claims data of four Italian regions (Lombardy, Veneto, Lazio, and Sardinia). Analytical datasets were created using an open-source tool for distributed analysis. To link the National Transplant Information System to the regional transplant cohorts, a semi-deterministic record linkage procedure was performed. Overall, 6,914 transplant patients from 2009–19 were identified: 4,029 (58.3%) for kidney, 2,219 (32.1%) for liver, 434 (6.3%) for heart, and 215 (3.1%) for lung. As expected, demographic and clinical characteristics showed considerable variability among organ settings. Although the triple therapy in terms of CNI + antimet/mTOR + steroids was widely dispensed for all settings (63.7% for kidney, 33.5% for liver, 53.3% for heart, and 63.7% for lung), differences in the active agents involved were detected. The CESIT network represents a great opportunity to study several aspects related to the use, safety, and effectiveness of post-transplant maintenance immunosuppressive therapy in real practice.
Abstract
Background
Very scanty evidence is available on factors influencing the choice of immunosuppressive drug therapy after kidney transplantation.
Methods
An Italian multiregional real-world ...study was conducted integrating national transplant information system and claims data. All patients undergoing kidney transplantation for the first time during 2009–2019 (incident patients) were considered. Multilevel logistic models were used to estimate Odds Ratio (OR) and corresponding 95% Confidence intervals. Factors with statistically significance were identified as characteristics associated with treatment regimens: cyclosporin-CsA vs tacrolimus-Tac and, within the latter group, mTOR inhibitors vs mycophenolate-MMF.
Results
We identified 3,622 kidney patients undergoing transplantation in 17 hospitals located in 4 Italian regions, 78.3% was treated with TAC-based therapy, of which 78% and 22% in combination with MMF and mTOR, respectively. For both comparison groups, the choice of immunosuppressive regimens was mostly guided by standard hospital practices. Only few recipient and donor characteristics were found associated with specific regimen (donor/receipt age, immunological risk and diabetes).
Conclusions
The choice of post-renal transplant immunosuppressive therapy seems to be mostly driven by standard Centre practices, while only partially based on patient’s characteristics and recognized international guidelines.
High‐concentration photovoltaic (HCPV) systems are one of the most promising technologies for the generation of renewable energy with high‐conversion efficiency. Their development is still at an ...early stage, but the possibility of integrating high‐concentration systems into buildings offers new opportunities to achieve the net‐zero‐energy building goal. Herein, the optical and energetic performance of a hybrid daylighting−HCPV prototype based on pure‐ or doped‐silica optical fibers (OFs) to guide 2000× concentrated sunlight inside the buildings is evaluated. There, the light can either be used to illuminate interior spaces or projected on solar cells to generate electricity. The system equipped with a single 400 μm core‐diameter OF is demonstrated to achieve a total efficiency of 15% and an optical efficiency of 45%.
Sunlight concentrator coupled to commercial silica optical fiber enables to guide solar light indoors to produce electric power by a daylighting/high‐concentration photovoltaic system with multijunction cells. Tests shows evidence that pure‐silica core fibers transmit 2000× concentrated light without degradation and with an efficiency of 15%
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