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CD1c presents lipid-based antigens to CD1c-restricted T cells which are thought to be a major component of the human T cell pool. The study of CD1c-restricted T cells, however, is hampered by the presence of an abundantly expressed CD1c-binding partner on blood cells distinct to the T cell receptor (TCR), confounding analysis of TCR-mediated CD1c tetramer staining. Here, we identify the CD36 family (CD36, CD36-L1 and CD36-L2) as novel ligands for CD1c, CD1b and CD1d proteins, and show that CD36 is the receptor responsible for non-TCR-mediated CD1c tetramer staining of blood cells. Moreover, CD36-blockade enables tetramer-based identification of CD1c-restricted T cells and clarifies identification of CD1b- and CD1d-restricted T cells. We use this technique to characterise CD1c-restricted T cells ex vivo and show diverse phenotypic features, TCR repertoire and antigen-specific subsets. Accordingly, this work will enable further studies into the biology of CD1 and human CD1-restricted T cells.One Sentence SummaryCD1 molecules bind CD36 family members and blockade of this interaction facilitates the study of CD1-restricted T cells.

Tissue-resident memory (TRM) CD8 T cells survey a range of non-lymphoid mucosal tissues where they rapidly mediate clearance of viral infections at the entry portals. Vaccines that establish CD8 TRM cells in the cervicovaginal mucosa hold promise for effective immunity against sexually transmitted HIV. We demonstrate that HIV-specific CD8 TRM cells can be established in the murine vaginal mucosa using a combined intranasal and intravaginal mucosal immunization with recombinant influenza-HIV vectors. Using in situ tetramer immunofluorescence microscopy, we found that this mucosally administered prime-boost immunization also resulted in the durable seeding of CD8 T cells in the frontline vaginal epithelial compartment as opposed to the vaginal submucosa. Upon cognate antigen recognition within the vaginal mucosa, these HIV-specific CD8 TRM cells rapidly initiated a tissue-wide state of immunity. The activation of HIV-specific CD8 TRM cells resulted in the upregulation of endothelial vessel addressin expression and substantial recruitment of both adaptive and innate immune cells in the vaginal mucosa. These findings suggest that the epithelial localization of HIV-specific CD8 TRM cell populations and their capacity to rapidly activate both arms of the immune system could significantly augment frontline defenses against vaginal HIV infection.

This paper introduces the concept of spin-orbit-torque-MRAM (SOT-MRAM) based physical unclonable function (PUF). The secret of the PUF is stored into a random state of a matrix of perpendicular SOT-MRAMs. Here, we show experimentally and with micromagnetic simulations that this random state is driven by the intrinsic nonlinear dynamics of the free layer of the memory excited by the SOT. In detail, a large enough current drives the magnetization along an in-plane direction. Once the current is removed, the in-plane magnetic state becomes unstable evolving towards one of the two perpendicular stable configurations randomly. In addition, an hybrid CMOS/spintronics model is used to evaluate the electrical characteristics of a PUF realized with an array of 16x16 SOT-MRAM cells. Beyond robustness against voltage and temperature variations, hardware authentication based on this PUF scheme has additional advantages over other PUF technologies such as non-volatility (no power consumption in standby mode), reconfigurability (the secret can be rewritten), and scalability. We believe that this work is a step forward the design of spintronic devices for application in security., 18 pages, 7 figures

Engineering the properties of nanoparticles (NPs) to limit non-specific cellular interactions is critical for developing effective drug delivery systems. In this study we investigate the differences in non-specific cell association between polymer NPs prepared with linear polyethylene glycol (PEG) and brush PEG both in vitro and ex vivo. Most studies to investigate the non-fouling properties of NPs have been performed using cell-line based assays. However, in this study we demonstrate a whole blood assay using fresh human blood. It is likely this assay reflects more accurately the fate of NPs when injected into human blood in vivo. Non-linear PEG analogues such as poly(poly(ethylene glycol)methacrylate) (PEGMA) are attractive alternatives to linear PEG as hydrophilic coatings for NP drug delivery systems due to their simple and versatile synthesis. We prepared NPs composed of a poly(2-diethylamino)ethyl methacrylate (PDEAEMA) core and a diblock copolymer of PDEAEMA and either linear PEG or brush PEGMA. These NPs depend on low-fouling properties of the hydrophillic PEG coating to avoid uptake by the mononuclear phagocyte system (MPS). In vitro cell association assays showed brush PEGMA NPs exhibited lower association with 3T3 fibroblast and C1R lymphoblast cells compared to linear PEG NPs. In an ex vivo whole blood assay, brush PEGMA nanoparticles showed similar low association with monocytes and granulocytes as linear PEG NPs with a similar length PEG component. Higher association with blood cells was observed for NPs containing a lower molecular weight PEGMA component, despite having the same molecular weight as the linear PEG NPs (2 kDa). The results demonstrate that trends observed in cell-lines are not always consistent with assays in more complex systems such as blood. Based on these results the reported PEGMA NPs are attractive alternatives to our previously reported linear PEG NPs.

In this work three-dimensional (3-D) numerical simulations, validated by the experimental measurements of a reference cell, have been performed to optimize the rear contact geometry of a PERC-type solar cell, featuring a high sheet resistance (140 Ω/sq) phosphorus-doped emitter and a front-side metallization with narrow and highly-conductive electro-plated copper lines (40 μm wide) on lowly resistive Ti contacts. The simulation results show that an optimization of the rear point contact design potentially leads to an efficiency improvement of 0.68%abs compared to the reference cell.

The mechanisms by which hepatitis B virus (HBV) establishes and maintains chronic hepatitis B infection (CHB) are poorly defined. Innate immune responses play an important role in reducing HBV replication and pathogenesis. HBV has developed numerous mechanisms to escape these responses, including the production of the secreted hepatitis B e antigen (HBeAg), which has been shown to regulate antiviral toll-like receptor (TLR) and interleukin-1 (IL-1) signaling. IL-18 is a related cytokine that inhibits HBV replication in hepatoma cell lines and in the liver through the induction of gamma interferon (IFN-γ) by NK cells and T cells. We hypothesized that HBV or HBV proteins inhibit IFN-γ expression by NK cells as an accessory immunomodulatory function. We show that HBeAg protein inhibits the NF-κB pathway and thereby downregulates NK cell IFN-γ expression. Additionally, IFN-γ expression was significantly inhibited by exposure to serum from individuals with HBeAg-positive but not HBeAg-negative chronic HBV infection. Further, we show that the HBeAg protein suppresses IL-18-mediated NF-κB signaling in NK and hepatoma cells via modulation of the NF-κB pathway. Together, these findings show that the HBeAg inhibits IL-18 signaling and IFN-γ expression, which may play an important role in the establishment and/or maintenance of persistent HBV infection. IMPORTANCE It is becoming increasingly apparent that NK cells play a role in the establishment and/or maintenance of chronic hepatitis B infection. The secreted HBeAg is an important regulator of innate and adaptive immune responses. We now show that the HBeAg downregulates NK cell-mediated IFN-γ production and IL-18 signaling, which may contribute to the establishment of infection and/or viral persistence. Our findings build on previous studies showing that the HBeAg also suppresses the TLR and IL-1 signaling pathways, suggesting that this viral protein is a key regulator of antiviral innate immune responses.

In this work we propose a methodology based on a mixed-mode simulation approach to evaluate the impact of finger interruptions in the front-side metallization on the solar cell performance. We apply the proposed methodology to typical finger profiles realized with double screen-printing technology. The efficiency degradation induced by finger interruptions is studied as a function of interruption size, interruption position, number of interruptions and finger resistivity. © 2012 Elsevier Ltd. All rights reserved.

Control of persistent intracellular pathogens such as human immunodeficiency virus type 1 (HIV-1) requires cell-mediated immunity. CD8+ cytotoxic T lymphocytes (CTL) eliminate virus-infected cells by recognizing and lysing cells presenting viral peptides on cell surface major histocompatibility complex (MHC) class I molecules. HIV-1-specific CD8+-T-cell responses temporally correlate with reduced viremia during acute infection prior to the appearance of virus-specific antibodies (6, 20). Depletion of CD8+ T cells in macaques chronically infected with simian immunodeficiency virus (SIV) results in brisk rises in viremia (31). CD4+-T-helper-cell responses are required to maintain effective virus-specific CD8+-T-cell immunity. The generation of T-cell immune responses correlates with the control of viremia following challenge of macaques with chimeric SIV/HIV-1 (5, 22). Measuring broad functional T-cell immunity in outbred subjects of unknown MHC genotype generally relies on the detection of antigen-specific gamma interferon (IFN-γ) production from T cells (17). In addition to secreting IFN-γ, an important cytokine mediator of cell-mediated immunity, T cells undergo proliferation and migration and release other effector molecules that facilitate their critical function during a viral infection: clearance of virus-infected cells in vivo. Previous murine studies have utilized fluorescent syngeneic splenocytes pulsed with known T-cell epitopes to sensitively measure virus-specific elimination in vivo (1, 7, 12, 25). No assessment of in vivo T-cell recognition and clearance of SIV/HIV-1 in nonhuman primates has previously been undertaken. There is an urgent need to induce or enhance HIV-specific T-cell immunity to prevent or control HIV disease. Safely inducing SIV- or HIV-1-specific CD4+ and CD8+ T cells in outbred nonhuman primates or in humans by vaccination generally requires DNA and/or live vaccine vectors that express foreign antigens within cells (2, 5, 19, 33). Peptide or protein approaches to induce CD8+-T-cell responses in primates have previously required ex vivo expansion of sterile antigen-presenting cell fractions such as monocyte-derived dendritic cells (26, 34). Although monocyte-derived dendritic cells loaded with inactivated SIV virions show promise for the control of SIV infection in macaques, such techniques will not be widely applicable since prolonged sterile culture is required (23). More feasible immunotherapy methods are needed. In this study, we describe a novel in vivo killing (IVK) assay using overlapping 15-mer peptide pools pulsed onto autologous fluorescently labeled peripheral blood mononuclear cells (PBMC) to measure SIV/HIV-1 vaccine-specific T-cell immunity in outbred pigtail macaques. When we analyzed SIV/HIV-1-specific immunity by standard techniques in the weeks following the IVK assays, a marked enhancement of virus-specific CD8+- and CD4+-T-cell immunity was induced.

In this work we investigate the impact of a non-uniform finger in the front-side metallization on the performance of c-Si solar cells. For this purpose, we propose a methodology based on a mixed-mode simulation approach, which allows evaluating the solar cell properties by performing both numerical device simulations and circuit simulations. The finger roughness profile is modeled by means of Gaussian function. The impact of roughness on the solar cell efficiency is studied as a function of mean finger height, mean finger width and finger resistivity. The proposed methodology has been applied to typical roughness profiles realized with two different metallization techniques, the conventional single screen-printing (SP) and the double screen-printing (DP).

Viene presentato il caso di un neonato affetto da stenosi ileale sottoposto a trattamento correttivo laparo-assistito.

Vaccination of sheep with a plasmid bearing the full length gene for the tick antigen Bm86 either alone or co-administered with plasmid carrying the ovine genes for the cytokines, granulocyte and macrophage colony stimulating factor (GM-CSF) or interleukin (IL)-1beta induced a relatively low level of protection against subsequent tick infestation. This tick damage reached statistical significance only for the groups which were vaccinated with plasmid encoding for Bm86, co-administered with plasmid encoding for ovine GM-CSF. Antibody titres measured against Bm86 were also low in all groups injected with the Bm86 DNA vaccine. Antibody production and anti-tick effect were significantly less than that achieved by two vaccinations with recombinant Bm86 protein. In all cases only a low level of antigen-specific stimulation of peripheral blood lymphocytes was recorded, as measured either by the incorporation of tritiated thymidine or the release of IFN-gamma. Injection of DNA encoding for Bm86, either alone or with co-administered cytokine genes, did however prime for a strong subsequent antibody response following a single injection of recombinant Bm86 protein in adjuvant. Antibody production nevertheless appeared to be slightly less effective than following two vaccinations with recombinant protein. The persistence of antibody following vaccination was the same regardless of the method of primary sensitization. In all cases the half-life of the antibody response was approximately 40-50 days indicating that, in contrast to results reported in mice, DNA vaccination in sheep did not result in sustained antibody production.

Numerical modeling represent a powerful approach to investigate the physical loss mechanisms that limit the conversion efficiency of solar cells. In this paper, a comprehensive analysis of the different loss mechanisms affecting the performance of a conventional c-Si solar cell, such as optical losses, recombination losses and parasitic resistive losses, has been performed by means of numerical device simulations. Moreover, a detailed quantification of the impact of the different recombination mechanisms within the cell has been carried out through dark current-voltage simulations, both for a conventional c-Si solar cell and a high-efficiency selective emitter c-Si solar cell.

The selective emitter (SE) design, featuring lower doped areas between the front contact fingers and higher doped areas underneath the front metallization, is crucial to improve the performance at the front side of a monocrystalline (c-Si) silicon solar cell. One of the most interesting and promising low-cost SE process consists of the screen printing of a phosphorus-doped paste, allowing a separate optimization of the doping profiles in the metallized and nonmetallized front-side areas. By referring to this kind of process, this paper presents a simulation study with a decoupled analysis on the effect of the lowly doped and highly doped profiles on the performance of an SE solar cell, by means of 2-D electro-optical numerical device simulations. Moreover, by exploiting the 2-D modeling, the effect of the alignment tolerance used in the SE diffusion process for the subsequent metallization process has been also investigated. Numerical results show that the adoption of an optimized design for the SE cell can lead to an efficiency improvement above 0.4%abs compared with the 75 Ω/sq homogeneous emitter reference cell.

In this paper we discuss the effect of shunt resistance on the electro-optical characteristics of multicrystalline silicon (mc-Si) solar cells at different illumination levels. The analysis is based on combined electro-optical characterization and thermographic measurements of solar cells with similar efficiencies, but with different shunt resistance levels. In order to understand how the shunt resistance can affect the performance of mc-Si solar cells, a special setup for J-V characterization at several illumination levels was developed. Results indicate that (i) a low shunt resistance is strongly correlated to the presence of hot spots, which can be identified by means of infrared thermography; (ii) solar cells with different shunt resistance levels can show significantly different fill factors and efficiencies, particularly at low irradiation levels. This can strongly influence the reliability of modules at low illumination conditions; (iii) the electrical characteristics of mc-Si solar cells can be modeled with good results, by considering the equivalent two-diode electrical model and solving it by a circuit simulator like SPICE.

Antibodies (Abs) that mediate antibody-dependent cellular cytotoxicity (ADCC) activity against HIV-1 are of major interest. A widely used method to measure ADCC Abs is the rapid and fluorometric antibody-dependent cellular cytotoxicity (RFADCC) assay. Antibody-dependent killing of a labelled target cell line by PBMC is assessed by loss of intracellular CFSE but retention of membrane dye PKH26 (CFSE-PKH26 +). Cells of this phenotype are assumed to be derived from CFSE + PKH26 + target cells killed by NK cells. We assessed the effector cells that mediate ADCC in this assay. Backgating analysis and phenotyping of CFSE-PKH26 + revealed that the RFADCC assay's readout mainly represents CD3-CD14 + monocytes taking up the PKH26 dye. This was confirmed for 53 HIV + plasma-purified IgG samples when co-cultured with PBMC from three separate healthy donors. Emergence of the CFSE-PKH26 + monocyte population was observed upon co-culture of targets with purified monocytes but not with purified NK cells. Image flow cytometry and microscopy showed a monocyte-specific interaction with target cells without typical morphological changes associated with phagocytosis, suggesting a monocyte-mediated ADCC process. We conclude that the RFADCC assay primarily reflects Ab-mediated monocyte function. Further studies on the immunological importance of HIV-specific monocyte-mediated ADCC are warranted.

The adoption of local point contacts at the back surface of high-efficiency monocrystalline silicon solar cells is strategic in order to reduce the recombination losses at the rear side of the device. However, the reduction of the rear-contact surface leads to an increase of series resistance losses. In this paper, we present an extensive analysis based on 3-D optoelectronic numerical device simulations in order to highlight the dependence of the conversion efficiency on the main geometrical and technological parameters of the cell, such as the pitch and the size of the rear point contacts and the substrate resistivity. A state-of-the-art device simulator has been successfully adopted in order to accurately solve the transport equations in the semiconductor by taking into account all the loss mechanisms that are crucial in order to address the design of the cell.

In this work we investigate c-Si solar cells in which a two steps (double) screen-printing is implemented for the front contact in order to increase the aspect ratio of the fingers. To this purpose numerical simulations are performed on a solar cell and metallization properties are defined according to experimental data. The analysis of solar cells with conventional single screen-printing is also performed for comparison. In agreement with experiments we show the efficiency improvement of double printing over single printing. The analysis of electrical parameters (fill factor, short-circuit current and open-circuit voltage) allows to understand the source of the enhanced efficiency.

Two-dimensional (2-D) numerical simulations have been performed to investigate the impact of the doping profile in the metal-contacted highly-doped regions for c-Si selective emitter (SE) solar cells. Numerical results show that the doping profile under the metallization significantly influences the recombination effects on the front-side of the SE cell and consequently its performance. A strong impact on the short-circuit current density of the solar cell has been seen. This is mainly due to the inclusion of large alignment tolerances used in the SE diffusion for the subsequent metallization process, leading to broad highly-doped areas. In this regard, a quantitative analysis of this effect has been carried out. The results reveal that an improved alignment, allowing a reduction of the alignment tolerances, leads to a wider process window of doping profiles and hence better SE cell performance.

The improvement of solar cell efficiency requires device optimization, including the careful design of contacts and doping profiles, and the implementation of light trapping strategies. In this context, electro-optical numerical simulation is essential to analyze the physical mechanisms that limit the cell efficiency and lead to design trade-offs. In this work we discuss the calibration of the relevant physical models for electrical simulation and we put in evidence important limitations of the most common adopted optical simulators.

Further advances are required in understanding protection from AIDS by T-cell immunity. We analyzed a set of multigenic simian/human immunodeficiency virus (SHIV) DNA and fowlpox virus priming and boosting vaccines for immunogenicity and protective efficacy in outbred pigtail macaques. The number of vaccinations required, the effect of DNA vaccination alone, and the effect of cytokine (gamma interferon) coexpression by the fowlpox virus boost was also studied. A coordinated induction of high levels of broadly reactive CD4 and CD8 T-cell immune responses was induced by sequential DNA and fowlpox virus vaccination. The immunogenicity of regimens utilizing fowlpox virus coexpressing gamma interferon, a single DNA priming vaccination, or DNA vaccines alone was inferior. Significant control of a virulent SHIV challenge was observed despite a loss of SHIV-specific proliferating T cells. The outcome of challenge with virulent SHIV mn229 correlated with vaccine immunogenicity except that DNA vaccination alone primed for protection almost as effectively as the DNA/fowlpox virus regimen despite negligible immunogenicity by standard assays. These studies suggest that priming of immunity with DNA and fowlpox virus vaccines could delay AIDS in humans.

Between 0,7-3% of pediatric patients may require resuscitation during hospital stay. The physicians of the Pediatric Intensive Care Unit of the C.O.U. Anesthesia and Intensive Care-Baroncini developed a plan for the management of pediatric emergencies inside the Department of Pediatric Medical and Surgical Sciences. The plan consisted of: the drawing up of a PI 34-Procedure; the preparation and implementation of a training course for doctors and nurses; the purchase of 12 emergency-trolleys according to the Broselow Pediatric Resuscitation Measuring Tape and the implementation of a specific system for the emergency-call. Precise duty for anesthesiologists and intensivists is the emergency- planning and management, in order to diffuse the medical knowledge needed to assist patients requiring vital functions support. The management of the intra-hospital pediatric emergencies is strictly dependent on the training of the staff, based on a specific support algorithm, and specific equipment for the different ages.

Accidental aspiration of a foreign body (FB) is an event which is reasonably frequent and dramatic in children and is still today one of the main causes of death due to accidents at home in children up to three-four years of age. The severity of the clinical picture varies according to the size, shape, type and site of arrest of the material aspirated and can be associated with both severe asphyxial forms and forms with insidious and vague symptoms which are difficult to diagnose correctly. A late diagnosis is however a fairly common event in literature. An anamnesis suggesting probable aspiration in a child under the age of 3 should direct doctors towards diagnostic and operative endoscope examinations of the patient, even where there is a negative clinical and radiological picture. Organic material, mainly peanuts, represented 60-75% of the findings, particularly in the 0-3 year age-band. In the other of cases inorganic material was extracted from school-age children. Aspiration of a FB exposes the patient to risk of serious complications and sequelae. Antibiotic, dexamethasone therapy and the ventilation support in the CPAP helped to avoid post-extractive sequelae. Prevention should in any case be the primary aim as regards to aspiration of foreign bodies in children. This should be stimulated by appropriate educational campaigns to raise awareness. The study included 62 child patients observed in the Department of Anesthesia and Intensive Care of the S.Orsola-Malpighi Hospital of Bologna over the last 11 years who were admitted for suspected FB aspiration.

A suitable perioperative fluid therapy during paediatric anaesthesia presupposes a valuation of renal function and the preoperative fluid and electrolyte imbalance, a precise knowledge of fluid requirements and the physiological stress responses to surgery in different paediatric groups. Fluid administration must be suited to the pathology of the patients and surgical approach. It must replace the deficits from the preoperative status (including fasting), provide maintenance fluid and correct intraoperative translocated fluids and blood loss. Fluid management requires reduced hypotonic solution in order to prevent hyponatremia and avoid excessive amount of glucose which can be harmful. In order to prevent the dangers from blood transfusions you need to estimate the intraoperative loss and follow the "acceptable hematocrit" values. Rational intraoperative fluid management reduces perioperative morbidity and mortality.

27th European Photovoltaic Solar Energy Conference and Exhibition; 181-184, Small size silicon concentrator solar cells have been developed showing good performance in low and medium concentration range. In this work we describe the fabrication technology, characterization and modeling of these cells. The cell conversion efficiency, Internal Quantum Efficiency (IQE), Open Circuit Voltage (VOC) and Short Circuit Current Density (JSC) were evaluated in the 1-200 Suns concentration range. The conversion efficiency is of 20.8% at 60 Suns and higher than 18.6% up to 200 Suns. The dependence of JSC on the concentration factor has been observed to be super-linear, with an 8% excess JSC at 200 Suns. Numerical simulations, calibrated and optimized to take into account the carrier recombination and mobility in high injection condition, match the experimental measurements and correctly predict the JSC super-linearity. This effect has been further investigated and explained by the enhancement of electric field in the base region, allowing an improvement of the minority carriers collection efficiency. Finally, numerical simulations, validated by the experimental measurements, were applied to optimize the cell design in terms of front metal finger pitch for different concentration levels.

27th European Photovoltaic Solar Energy Conference and Exhibition; 1453-1456, In this paper we propose a three-dimensional (3-D) distributed electrical network for the modelling of solar cells. The developed tool is based on a network of repetitive elementary cells, each modeled by a two-diode electrical circuit and allows to account for the transport through the emitter, the fingers and the busbars. Moreover, the tool is able to account for the non-uniformity in the solar cell. In order to validate our tool, we calibrate the electrical parameters according to experimental measurements on multicrystalline-silicon (mc-Si) solar cells. By using the thermographic analysis, we detect hot spot regions inside the mc-Si devices and we model them by means of local shunting in our tool. The presence of local shunting, due to localized crystal defects, results in a degradation of the open-circuit voltage, of the fill factor and then of the overall power conversion efficiency.