Ga2O3 polymorphs: Tailoring the epitaxial growth conditions

Gallium oxide is a wide bandgap n-type semiconductor highly interesting for optoelectronic applications (e.g., power electronics and solar blind UV photodetectors). Besides its most thermodynamically stable monoclinic β phase, Ga2O3 can crystallize in different polymorphs; among them the corundum α and the orthorhombic ϵ phases are the most promising ones. In this review we focus on the main aspects that promote the nucleation and stable growth of these Ga2O3 polymorphs. Particular emphasis is given to the ϵ phase since it is recently gaining increasing attention in the scientific community because of: (i) its higher lattice symmetry with respect to β-Ga2O3, which could favour the realization of heterostructures, (ii) the possibility to be grown on cheap sapphire substrates and (iii) its peculiar piezoelectric properties. While the growth of β-Ga2O3 is widely studied and understood, a thorough and comprehensive analysis of the chemical and physical aspects that allow for the stabilization of the metastable Ga2O3 phases with different synthesis methods is still missing. Therefore, the present review aims at filling this gap, by analysing the relevant growth parameters for several growth techniques (MOVPE, HVPE, mist-CVD, MBE, and PLD), highlighting similarities and differences, looking for a unified framework to understand the growth and nucleation of different Ga2O3 polymorphs. As a conclusion, we highlight practical guidelines for the deposition of the different Ga2O3 polymorphs with all the discussed thin film growth techniques

Interrelationship between serum and sputum inflammatory mediators in chronic obstructive pulmonary disease

Little is known about airway inflammatory markers in chronic obstructive pulmonary disease (COPD). The objective of the present study was to identify and try to correlate pulmonary and peripheral blood inflammatory markers in COPD. In a cross-sectional study on patients with stable COPD, induced sputum and blood samples were collected for the determination of C-reactive protein, eosinophilic cationic protein, serum amyloid A protein, a-1 antitrypsin (a-1AT), and neutrophil elastase. Twenty-two patients were divided into two groups according to post-bronchodilator forced expiratory volume in the first second (%FEV1): group 1 (N = 12, FEV1 <40%) and group 2 (N = 10, FEV1 ³40%). An increase in serum elastase, eosinophilic cationic protein and a-1AT was observed in serum markers in both groups. Cytology revealed the same total number of cells in groups 1 and 2. There was a significantly higher number of neutrophils in group 1 compared to group 2 (P < 0.05). No difference in eosinophils or macrophages was observed between groups. Serum elastase was positively correlated with serum a-1AT (group 1, r = 0.81, P < 0.002 and group 2, r = 0.83, P < 0.17) and negatively correlated with FEV1 (r = -0.85, P < 0.03 and -0.14, P < 0.85, respectively). The results indicate the presence of chronic and persistent pulmonary inflammation in stable patients with COPD. Induced sputum permitted the demonstration of the existence of a subpopulation of cells in which neutrophils predominated. The serum concentration of all inflammatory markers did not correlate with the pulmonary functional impairment

Antimicrobial susceptibility to zinc bacitracin of Clostridium perfringens of rabbit origin

Zinc bacitracin is widely used in Italian rabbit farms to control both Epizootic Rabbit Enteropathy (ERE) and clostridiosis, and field results demonstrate useful activity. Nevertheless, data regarding the in vitro efficacy of zinc bacitracin against clostridia of rabbit origin are not available. In this study, the minimal inhibitory concentrations (MICs) of zinc bacitracin were evaluated in 123 C. perfringens strains isolated from rabbits in Italian fattening units. The agar dilution method was performed in Brucella Agar supplemented with laked sheep blood, haemin and vitamin K1, as recommended in NCCLS document M11-A6. Most strains (94.3%) had low MIC values (£ 0.5 mg/ml), and a few strains (4%) were inhibited by a concentration of 1 mg/ml. Two isolates (1.6%) had a MIC value of 16mg/ml. The MIC values of ATCC reference strains showed a good fit between each batch. MIC required to inhibit the 90% of organisms was 0.5 mg/ml and the presence of only two strains with MIC=16 mg/ml revealed the susceptibility to zinc bacitracin of Italian isolates of C. perfringens from rabbit and the absence of acquired resistance.Agnoletti, F.; Bacchin, C.; Bano, L.; Passera, A.; Favretti, M.; Mazzolini, E. (2007). Antimicrobial susceptibility to zinc bacitracin of Clostridium perfringens of rabbit origin. World Rabbit Science. 15(1):19-22. doi:10.4995/wrs.2007.609192215

A novel A33 promoter-based conditionally replicative adenovirus suppresses tumor growth and eradicates hepatic metastases in human colon cancer models

Purpose: A33 antigen is a membrane-bound protein expressed in intestinal epithelium that is overexpressed in 95% of primary and metastatic colorectal carcinomas but is absent in most epithelial tissues and tumor types. We hypothesized that A33 promoter might be useful in the design of a conditionally replicative adenovirus for the treatment of colorectal cancer (CRC). Experimental Design: We cloned an A33 promoter fragment (A33Pr) that extends from -105 to +307 bp. Using luciferase activity as a reporter gene, we showed that A33Pr was active inCRC cell lines. We next constructed a conditionally replicative adenovirus named AV22EL where E1A was placed under the control of A33Pr. The tumor-specific oncolytic effect of AV22EL was investigated both in vitro and in vivo. Results: AV22EL induced specific in vitro lysis of human CRC cell lines that expressed A33 and have negligible lytic capacity on cells that lacked or hadminimal A33 expression, including normal human colonic cells. In vivo, a marked reduction of tumor growth and increased long-term survival rates were observed in nude mice xenografted with s.c. CRC tumors. Combination with 5-fluorouracil induced an additive effect in vitro with no toxic effects in vivo. Remarkably, AV22EL completely eliminated established hepatic metastases in >90% of mice and restored hepatic function according to biochemical parameters. Its systemic administration induced E1A expression only in the hepatic metastasis but not in normal organs. Conclusions: These data show that AV22EL is a stringently regulated and potent oncolytic agent for the treatment of CRC.Facultad de Ciencias Veterinaria

Cellular entry of nanoparticles via serum sensitive clathrin-mediated endocytosis, and plasma membrane permeabilization

Increasing production and application of nanomaterials raises significant questions regarding the potential for cellular entry and toxicity of nanoparticles. It was observed that the presence of serum reduces the cellular association of 20 nm carboxylate-modified fluorescent polystyrene beads up to 20-fold, relative to cells incubated in serum-free media. Analysis by confocal microscopy demonstrated that the presence of serum greatly reduces the cell surface association of nanoparticles, as well as the potential for internalization. However, both in the presence and absence of serum, nanoparticle entry depends upon clathrin-mediated endocytosis. Finally, experiments performed with cells cooled to 4°C suggest that a proportion of the accumulation of nanoparticles in cells was likely due to direct permeabilization of the plasma membrane

Tuning electrical properties of hierarchically assembled Al-doped ZnO nanoforests by room temperature Pulsed Laser Deposition

Large surface area, 3D structured transparent electrodes with effective light management capability may represent a key component in the development of new generation optoelectronic and energy harvesting devices. We present an approach to obtain forest-like nanoporous/hierarchical Al-doped ZnO conducting layers with tunable transparency and light scattering properties, by means of room temperature Pulsed Laser Deposition in a mixed Ar:O2 atmosphere. The composition of the background atmosphere during deposition can be varied to modify stoichiometry-related defects, and therefore achieve control of electrical and optical properties, while the total background pressure controls the material morphology at the nano- and mesoscale and thus the light scattering properties. This approach allows to tune electrical resistivity over a very wide range (10^-1 - 10^6 Ohm*cm), both in the in-plane and cross-plane directions. Optical transparency and haze can also be tuned by varying the stoichiometry and thickness of the nano-forests

Exploring the Needs and Expectations of Expectant and New Parents for an mHealth Application to Support the First 1000 Days of Life: Steps toward a Co-Design Approach

To improve maternal and child health, it is essential to adhere to health-promoting and preventive measures. However, reliable information as well as effective tools are not easy to identify in this field. Our cross-sectional study investigated the needs and expectations of expectant and new mothers and fathers as potential primary users of a hypothetical application supporting the first 1000 days of life. Between May and August 2022, we recruited expectant and new parents by administering an 83-item 5-point Likert scale questionnaire related to the content, functionalities, and technical features of the hypothetical app. We stratified responses using sociodemographic characteristics and then performed ward hierarchical clustering. The 94 women and 69 men involved in our study generally agreed with the proposed content, but expressed low interest in certain app functionalities or features, including those related to the interaction mechanism and interactivity. Women were generally more demanding than men. Our findings, resulting from the engagement of end-users, may be useful for designers and technology providers to implement mHealth solutions that, in addition to conveying reliable information, are tailored to the needs and preferences of end-users in the first 1000 days of life

Improving efficacy of interleukin-12-transfected dendritic cells injected into murine colon cancer with anti-CD137 monoclonal antibodies and alloantigens

Intralesional administration of cultured dendritic cells (DCs) engineered to produce IL-12 by in vitro infection with recombinant adenovirus frequently displays eradicating efficacy against established subcutaneous tumors derived from the CT26 murine colon carcinoma cell line. The elicited response is mainly mediated by cytolytic T lymphocytes. In order to search for strategies that would enhance the efficacy of the therapeutic procedure against less immunogenic tumors, we moved onto malignancies derived from the inoculation of MC38 colon cancer cells that are less prone to undergo complete regression upon a single intratumoral injection of IL-12-secreting DCs. In this model, we found that repeated injections of such DCs, as opposed to a single injection, achieved better efficacy against both the injected and a distantly implanted tumor; that the use of semiallogeneic DCs that are mismatched in one MHC haplotype with the tumor host showed slightly better efficacy; and that the combination of this treatment with systemic injections of immunostimulatory anti-CD137 (4-1BB) monoclonal antibody achieved potent combined effects that correlated with the antitumor immune response measured in IFN-gamma ELISPOT assays. The elicited systemic immune response eradicates concomitant untreated lesions in most cases. Curative efficacy was also found against some tumors established for 2 weeks when these strategies were used in combination. These are preclinical pieces of evidence to be considered in order to enhance the therapeutic benefit of a strategy that is currently being tested in clinical trials. Supplementary Material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html

A novel A33 promoter-based conditionally replicative adenovirus suppresses tumor growth and eradicates hepatic metastases in human colon cancer models

Purpose: A33 antigen is a membrane-bound protein expressed in intestinal epithelium that is overexpressed in 95% of primary and metastatic colorectal carcinomas but is absent in most epithelial tissues and tumor types. We hypothesized that A33 promoter might be useful in the design of a conditionally replicative adenovirus for the treatment of colorectal cancer (CRC). Experimental Design: We cloned an A33 promoter fragment (A33Pr) that extends from -105 to +307 bp. Using luciferase activity as a reporter gene, we showed that A33Pr was active inCRC cell lines. We next constructed a conditionally replicative adenovirus named AV22EL where E1A was placed under the control of A33Pr. The tumor-specific oncolytic effect of AV22EL was investigated both in vitro and in vivo. Results: AV22EL induced specific in vitro lysis of human CRC cell lines that expressed A33 and have negligible lytic capacity on cells that lacked or hadminimal A33 expression, including normal human colonic cells. In vivo, a marked reduction of tumor growth and increased long-term survival rates were observed in nude mice xenografted with s.c. CRC tumors. Combination with 5-fluorouracil induced an additive effect in vitro with no toxic effects in vivo. Remarkably, AV22EL completely eliminated established hepatic metastases in >90% of mice and restored hepatic function according to biochemical parameters. Its systemic administration induced E1A expression only in the hepatic metastasis but not in normal organs. Conclusions: These data show that AV22EL is a stringently regulated and potent oncolytic agent for the treatment of CRC.Facultad de Ciencias Veterinaria