Rotavirus immunisation status affects the efficacy of Lacticaseibacillus rhamnosus GG for the treatment of children with acute diarrhoea: a meta-analysis

: The efficacy of Lacticaseibacillus rhamonosus GG (LGG) for the treatment of children with acute gastroenteritis has been debated based on most recent evidence. Previous evidence demonstrated that LGG mainly benefits children with Rotavirus infection compared to other aetiologies. However, Rotavirus immunisation (RVI) has been implemented worldwide since 2006. We aimed to investigate whether the efficacy of LGG in children with gastroenteritis vary according to RVI status. The MEDLINE, Embase and Cochrane library databases were searched for relevant randomised controlled trials (RCT) up to April 2022. The duration of diarrhoea and episodes lasting >48 h were considered as primary outcomes. The date of vaccine introduction and RVI coverage were reviewed for all countries where trials were conducted. Among the 15 RCTs included in the analysis (n=3,465), only 5 showed a low risk of bias. In RCT conducted before the introduction of RVI (n=2,932), LGG was effective in reducing the duration of diarrhoea compared with placebo or standard care (Median -23.80 h, 95% confidence interval (CI) -36.59 to -11.02]). Only 2 RCTs (n=1,072) reported data of populations partially immunised against Rotavirus with an overall coverage of 44 and 67%, respectively. In this population, LGG showed no efficacy in reducing the duration of diarrhoea (Median -5.34, 95%CI -12.9 to 2.22). Similarly, LGG reduced the risk of diarrhoea lasting >48 h in children not immunised against Rotavirus (RR 0.73, 95%CI 0.54-0.99), but not in population partially immunised (RR 0.98, 95%CI 0.87 to 1.11). The implementation of RVI might affect the efficacy of LGG modifying local epidemiology and susceptibility of the target population to selected probiotics

An Optimized U-Net for Unbalanced Multi-Organ Segmentation

Medical practice is shifting towards the automation and standardization of the most repetitive procedures to speed up the time-to-diagnosis. Semantic segmentation repre-sents a critical stage in identifying a broad spectrum of regions of interest within medical images. Indeed, it identifies relevant objects by attributing to each image pixels a value representing pre-determined classes. Despite the relative ease of visually locating organs in the human body, automated multi-organ segmentation is hindered by the variety of shapes and dimensions of organs and computational resources. Within this context, we propose BIONET, a U-Net-based Fully Convolutional Net-work for efficiently semantically segmenting abdominal organs. BIONET deals with unbalanced data distribution related to the physiological conformation of the considered organs, reaching good accuracy for variable organs dimension with low variance, and a Weighted Global Dice Score score of 93.74 ± 1.1%, and an inference performance of 138 frames per second. Clinical Relevance - This work established a starting point for developing an automatic tool for semantic segmentation of variable-sized organs within the abdomen, reaching considerable accuracy on small and large organs with low variability, reaching a 93.74 ± 1.1 % of Weighted Global Dice Score

A new route for the shape differentiation of cesium lead bromide perovskite nanocrystals with near-unity photoluminescence quantum yield

The ongoing interest in all-inorganic cesium lead bromide perovskite nanocrystals (CsPbBr3 NCs) is mainly due to their optical properties, in particular their high photoluminescence quantum yields (PLQYs). Three-precursor synthetic methods, in which the sources of the three elements (cesium, lead and bromine) constituting the perovskite scaffold are chemically independent, often succeed in the achievement of near-unity PLQY perovskite NCs. However, this class of synthetic approaches precludes the accessibility to crystal morphologies different from the traditional cuboidal ones. In order to upgrade three-precursor synthetic schemes to obtain more sophisticated morphologies-such as rods-we propose a conceptually original synthetic methodology, in which a potentially controllable stage of the reaction anticipates the fast crystallization promoted by cesium injection. To this purpose, lead oxide, 1-bromohexane (at different molar ratios with respect to lead) and the ligands (oleic acid and a suitable amine) in 1-octadecene are reacted at 160 °C for an incubation period of 30 min before cesium injection. During this stage and at high C6H13Br/PbO molar ratios, the bromide release from reactions between the ligands and 1-bromohexane promotes the evolution of [PbBr(2+n)]n- species as well as of two-dimensional [(RNH3)2(PbBr4)]n structures with a rod-like shape (aspect ratios ~10). These structures act as the templating agents for the subsequent crystallization promoted by cesium injection, ensuring the formation of near-unity PLQY nanorods in the presence of decylamine. Conversely, the pronounced decomposition of the preformed [(RNH3)2(PbBr4)]n structures preludes to the formation of near-unity PLQY nanocubes in the presence of hexylamine. The amine choice exerts also an important role in the emission stability of the corresponding NCs, since the nanocubes prepared in the presence of hexylamine maintain their near-unity PLQYs up to 90 days under ambient conditions. In addition to the long-term PLQY stability, the nanorods prepared with decylamine also exhibit a remarkable resistance to the presence of water, due to the compact and hydrophobic organic shell passivating the NC surface. These findings can contribute to the development of innovative synthetic methodologies for controlling the shape and stability of near-unity PLQY perovskite NCs

Size-tunable and stable cesium lead-bromide perovskite nanocubes with near-unity photoluminescence quantum yield

Stable cesium lead bromide perovskite nanocrystals (NCs) showing a near-unity photoluminescence quantum yield (PLQY), narrow emission profile, and tunable fluorescence peak in the green region can be considered the ideal class of nanomaterials for optoelectronic applications. However, a general route for ensuring the desired features of the perovskite NCs is still missing. In this paper, we propose a synthetic protocol for obtaining near-unity PLQY perovskite nanocubes, ensuring their size control and, consequently, a narrow and intense emission through the modification of the reaction temperature and the suitable combination ratio of the perovskite constituting elements. The peculiarity of this protocol is represented by the dissolution of the lead precursor (PbBr2) as a consequence of the exclusive complexation with the bromide anions released by thein situSN2reaction between oleylamine (the only surfactant introduced in the reaction mixture) and 1-bromohexane. The obtained CsPbBr3nanocubes exhibit variable size (ranging from 6.7 ± 0.7 nm to 15.2 ± 1.2 nm), PL maxima between 505 and 517 nm, and near-unity PLQY with a narrow emission profile (fwhm of 17-19 nm). Additionally, the NCs synthesized with this approach preserve their high PLQYs even after 90 days of storage under ambient conditions, thus displaying a remarkable optical stability. Through the rationalization of the obtained results, the proposed synthetic protocol provides a new ground for the direct preparation of differently structured perovskite NCs without resorting to any additional post-synthetic treatment for improving their emission efficiency and stability

In Situ Formation of Zwitterionic Ligands: Changing the Passivation Paradigms of CsPbBr3 Nanocrystals

CsPbBr3 nanocrystals (NCs) passivated by conventional lipophilic capping ligands suffer from colloidal and optical instability under ambient conditions, commonly due to the surface rearrangements induced by the polar solvents used for the NC purification steps. To avoid onerous postsynthetic approaches, ascertained as the only viable stability-improvement strategy, the surface passivation paradigms of as-prepared CsPbBr3 NCs should be revisited. In this work, the addition of an extra halide source (8-bromooctanoic acid) to the typical CsPbBr3 synthesis precursors and surfactants leads to the in situ formation of a zwitterionic ligand already before cesium injection. As a result, CsPbBr3 NCs become insoluble in nonpolar hexane, with which they can be washed and purified, and form stable colloidal solutions in a relatively polar medium (dichloromethane), even when longly exposed to ambient conditions. The improved NC stability stems from the effective bidentate adsorption of the zwitterionic ligand on the perovskite surfaces, as supported by theoretical investigations. Furthermore, the bidentate functionalization of the zwitterionic ligand enables the obtainment of blue-emitting perovskite NCs with high PLQYs by UV-irradiation in dichloromethane, functioning as the photoinduced chlorine source

Less Is More: Simplified Fluorene-Based Dopant-Free Hole Transport Materials Promote the Long-Term Ambient Stability of Perovskite Solar Cells

The stability of perovskite solar cells (PSCs) is greatly affected by the interface between the perovskite active layer and the hole transport material (HTM). The rational design of HTMs with effective anchoring to the perovskite surface is an emerging elegant strategy to promote compact and ordered interfaces that lead to highly efficient and stable PSCs. Herein, we propose two fluorene-based HTM molecular architectures (SCF1 and SCF2) derived from the popular yet expensive Spiro-OMeTAD. Their employment as dopant-free HTMs in standard triple-cation CsFAMA PSCs leads to superior device stability, with a T80 lifetime well above 1 year (431 days). Our combined theoretical and experimental study of the CsFAMA|HTM interface reveals that the improved adhesion of the SCF-HTMs to the perovskite layer is the key to minimize the non-radiative recombination, reduce the hole trap density, and enhance the long-term stability of the corresponding devices. The simplified structures of SCF1 and SCF2, obtained by removing the orthogonal fragment of the Spiro-OMeTAD scaffold, show a lower molecular distortion than Spiro-OMeTAD, thus promoting a favorable electronic interaction between the SCF-HTMs and the perovskite. This study provides useful design criteria for achieving highly stable PSCs including dopant-free HTMs with optimized adhesion to the perovskite surface