Chemical Doping of the Organic Semiconductor C8-BTBT-C8 Using an Aqueous Iodine Solution for Device Mobility Enhancement

The performance of organic field-effect transistors is still severely limited by factors such as contact resistance and charge trapping. Chemical doping is considered to be a promising key enabler for improving device performance, although there is a limited number of established doping protocols as well as a lack of understanding of the doping mechanisms. Here, a very simple doping methodology based on exposing an organic semiconductor thin film to an aqueous iodine solution is reported. The doped devices exhibit enhanced device mobility, which becomes channel-length independent, a decreased threshold voltage and a reduction in the density of interfacial traps. The device OFF current is not altered, which is in agreement with the spectroscopic data that points out that no charge transfer processes are occurring. Kelvin probe force microscopy characterization of the devices under operando conditions unambiguously proves that an important reduction of the contact resistance takes place after their exposition to the iodine solution, reaching almost ohmic contact

Laser Printing of Multilayered Alternately Conducting and Insulating Microstructures

Production of multilayered microstructures composed of conducting and insulating materials is of great interest as they can be utilized as microelectronic components. Current proposed fabrication methods of these microstructures include top-down and bottom-up methods, each having their own set of drawbacks. Laser-based methods were shown to pattern various materials with micron/sub-micron resolution; however, multilayered structures demonstrating conducting/insulating/conducting properties were not yet realized. Here, we demonstrate laser printing of multilayered microstructures consisting of conducting platinum and insulating silicon oxide layers by a combination of thermally driven reactions with microbubble-assisted printing. PtCl2 dissolved in N-methyl-2-pyrrolidone (NMP) was used as a precursor to form conducting Pt layers, while tetraethyl orthosilicate dissolved in NMP formed insulating silicon oxide layers identified by Raman spectroscopy. We demonstrate control over the height of the insulating layer between ∼50 and 250 nm by varying the laser power and number of iterations. The resistivity of the silicon oxide layer at 0.5 V was 1.5 × 1011 ωm. Other materials that we studied were found to be porous and prone to cracking, rendering them irrelevant as insulators. Finally, we show how microfluidics can enhance multilayered laser microprinting by quickly switching between precursors. The concepts presented here could provide new opportunities for simple fabrication of multilayered microelectronic devices

Incidence, risk factors, and outcome of BK polyomavirus infection after kidney transplantation

BACKGROUND Polyomavirus-associated nephropathy is a leading cause of kidney allograft failure. Therapeutic options are limited and prompt reduction of the net state of immunosuppression represents the mainstay of treatment. More recent application of aggressive screening and management protocols for BK-virus infection after renal transplantation has shown encouraging results. Nevertheless, long-term outcome for patients with BK-viremia and nephropathy remains obscure. Risk factors for BK-virus infection are also unclear. AIM To investigate incidence, risk factors, and outcome of BK-virus infection after kidney transplantation. METHODS This single-centre observational study with a median follow up of 57 (31-80) mo comprises 629 consecutive adult patients who underwent kidney transplantation between 2007 and 2013. Data were prospectively recorded and annually reviewed until 2016. Recipients were periodically screened for BK-virus by plasma quantitative polymerized chain reaction. Patients with BK viral load >= 1000 copies/mL were diagnosed BK-viremia and underwent histological assessment to rule out nephropathy. In case of BK-viremia, immunosuppression was minimized according to a prespecified protocol. The following outcomes were evaluated: patient survival, overall graft survival, graft failure considering death as a competing risk, 30-d-event-censored graft failure, response to treatment, rejection, renal function, urologic complications, opportunistic infections, new-onset diabetes after transplantation, and malignancies. We used a multivariable model to analyse risk factors for BK-viremia and nephropathy. RESULTS BK-viremia was detected in 9.5% recipients. Initial viral load was high (>= 10000 copies/mL) in 66.7% and low (= 50% (30% vs 14.6%, P = 0.0047), human leukocyte antigen (HLA) mismatching > 4 (26.7% vs 13.4%, P = 0.0110), and rejection within thirty days of transplant (21.7% vs 9.5%; P = 0.0073) was higher in the viremic group. Five-year patient and overall graft survival rates for patients with or without BK-viremia were similar. However, viremic recipients showed higher 5-year crude cumulative (22.5% vs 12.2%, P = 0.0270) and 30-d-event-censored (22.5% vs 7.1%, P = 0.001) incidences of graft failure than control. In the viremic group we also observed higher proportions of recipients with 5-year estimated glomerular filtration rate 50%, HLA mismatching > 4, and rejection were independent risk factors for BK-virus viremia whereas cytomegalovirus prophylaxis was protective. CONCLUSION Current treatment of BK-virus infection offers sub-optimal results. Initial viremia is a valuable parameter to detect patients at increased risk of nephropathy. Panel-reactive antibody > 50% and Afro-Caribbean ethnicity are independent predictors of BK-virus infection whereas cytomegalovirus prophylaxis has a protective effect

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background: The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization. Methods: Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog. Results: A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported. Conclusions: Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals

Chiral “doped” MOFs: an electrochemical and theoretical integrated study

This work reports on the electrochemical behaviour of Fe and Zn based metal-organic framework (MOF) compounds, which are “doped” with chiral molecules, namely: cysteine and camphor sulfonic acid. Their electrochemical behaviour was thoroughly investigated via “solid-state” electrochemical measurements, exploiting an “ad hoc” tailored experimental set-up: a paste obtained by carefully mixing the MOF with graphite powder is deposited on a glassy carbon (GC) surface. The latter serves as the working electrode (WE) in cyclic voltammetry (CV) measurements. Infrared (IR), X-ray diffraction (XRD) and absorbance (UV-Vis) techniques are exploited for a further characterization of the MOFs’ structural and electronic properties. The experimental results are then compared with DFT based quantum mechanical calculations. The electronic and structural properties of the MOFs synthesized in this study depend mainly on the type of metal center, and to a minor extent on the chemical nature of the dopant

Current fluctuations in polystyrene nano-compounds

The current fluctuations in a polystyrene matrix (PS) doped by gold nanoparticles (Au-NPs) and small conjugated molecules of 8-hydroxyquinoline (8HQ) have been characterized. The electrical properties of the PS composite allow using it as a responsive layer in non-volatile memory devices due to its switching capability between two well separated conducting states. The analysis of current fluctuations at fixed bias voltages showed the presence of two states in charge carrier transport regardless of the operating conducting state of the device. Moreover, noise spectra have been investigated in the low frequency region, allowing the estimation of charge relaxation times between current levels in the two memory states. The presence of these slow and large fluctuations can seriously affect the final electrical performances of this class of nanostructured memories

N-Palmitoiletanolamide micronizzata e transpolidatina nel trattamento del dolore pelvico cronico associato all’endometriosi

Il dolore pelvico cronico è un’entità complessa, la cui natura è tuttora enigmatica e per il quale esistono poche strategie terapeutiche universalmente efficaci. L’endometriosi è una patologia ginecologica, cronica e benigna, importante causa di dolore pelvico cronico, per la quale sono state sviluppate numerose terapie. L’obiettivo del nostro studio è stato valutare l’efficacia dell’ associazione di nuove molecole, l’ N-palmitoiletanolamide micronizzata e la transpolidatina, nel trattamento del dolore pelvico cronico correlato all’endometriosi. Materiali e metodi. Il presente studio, randomizzato e controllato, in doppio cieco a gruppi paralleli, ha coinvolto 54 pazienti con diagnosi laparoscopica di endometriosi suddivise in 3 gruppi di trattamento della durata di 3 mesi: associazione N-palmitoiletanolamide micronizzata e transpolidatina 200 mg + 20 mg 3 volte al giorno (gruppo A = 18 pz); placebo (gruppo B = 18 pz); singolo corso di Celecoxib 200 mg 2 volte al giorno (gruppo C = 18 pz). È stata valutata la severità dell’endometriosi pelvica (dolore pelvico, dismenorrea, dispareunia) prima e dopo terapia tramite questionario ad hoc e scala analogica visiva (VAS). Le differenze tra i gruppi sono state valutate mediante il test ANOVA Kruskal-Wallis per raffronti multipli non parametrici. Risultati. In tutti i gruppi si è osservata una marcata diminuzione del dolore pelvico. L’associazione N-palmitoiletanolamide micronizzata e transpolidatina è risultata più efficace del placebo, mentre il Celecoxib è risultato più efficace di entrambi. Conclusioni. L’associazione N-palmitoiletanolamide micronizzata e transpolidatina è efficace nel trattamento del dolore pelvico correlato all’endometriosi. Inoltre tale associazione può essere usata in pazienti che non possono ricevere altre terapi