Sparse decomposition and modeling of anatomical shape variation

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome.     

The Autophagy-Related Organelle Autophagoproteasome Is Suppressed within Ischemic Penumbra

The peri-infarct region, which surrounds the irreversible ischemic stroke area is named ischemic penumbra. This term emphasizes the borderline conditions for neurons placed within such a critical region. Area penumbra separates the ischemic core, where frank cell loss occurs, from the surrounding healthy brain tissue. Within such a brain region, nervous matter, and mostly neurons are impaired concerning metabolic conditions. The classic biochemical marker, which reliably marks area penumbra is the over-expression of the heat shock protein 70 (HSP70). However, other proteins related to cell clearing pathways are modified within area penumbra. Among these, autophagy proteins like LC3 increase in a way, which recapitulates Hsp70. In contrast, components, such as P20S, markedly decrease. Despite apparent discrepancies, the present study indicates remarkable overlapping between LC3 and P20S redistribution within area penumbra. In fact, the amount of both proteins is markedly reduced within vacuoles. Specifically, a massive loss of LC3 + P20S immuno-positive vacuoles (autophagoproteasomes) is reported here. This represents the most relevant sub-cellular alteration here described in cell clearing pathways within area penumbra. The functional significance of these findings remains to be determined and it will take a novel experimental stream to decipher the fine-tuning of such a phenomenon.     

A new technique for calibration in frequency of piezoelectric transducers

The calibration in frequency of piezoelectric transducers can be obtained by sending an ultrashort laser pulse (30 ps), generated by a mode-locked Nd:YAG laser, directly on the detector surface. Thanks to its short duration, the mode-locked pulse behaves as an excitation source of wide spectral content, so that the spectral analysis of the recorded electric signal gives direct information about the frequency response of the probe. In particular, we report a series of measurements on various transducers of several nominal frequencies and we show the different response of the probe to a focused laser beam to that of an unfocused one.     

Degradation and annealing of amorphous silicon solar cells by current injection: experiment and modeling

In this paper we report in detail on the effect of current injection in amorphous silicon solar cells. A set of devices has been degraded and then annealed at different current intensities. Device performances during the whole experiment have been monitored by current–voltage characteristics and quantum efficiency curves. It has been found that annealing rate increases with current intensity, while stabilized photovoltaic parameters decrease. Time evolution of efficiency and short-circuit current during degradation has been reproduced by a numerical device modeling, resulting in a pronounced increase of defects near the p–i interface. The model also demonstrated that annealing results are not well reproduced if current-induced annealing is not energy selective.     

The Role of Endothelium in COVID-19

The 2019 novel coronavirus, known as severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), is causing a global pandemic. The virus primarily affects the upper and lower respiratory tracts and raises the risk of a variety of non-pulmonary consequences, the most severe and possibly fatal of which are cardiovascular problems. Data show that almost one-third of the patients with a moderate or severe form of COVID-19 had preexisting cardiovascular comorbidities such as diabetes mellitus, obesity, hypertension, heart failure, or coronary artery disease. SARS-CoV2 causes hyper inflammation, hypoxia, apoptosis, and a renin–angiotensin system imbalance in a variety of cell types, primarily endothelial cells. Profound endothelial dysfunction associated with COVID-19 can be the cause of impaired organ perfusion that may generate acute myocardial injury, renal failure, and a procoagulant state resulting in thromboembolic events. We discuss the most recent results on the involvement of endothelial dysfunction in the pathogenesis of COVID-19 in patients with cardiometabolic diseases in this review. We also provide insights on treatments that may reduce the severity of this viral infection.     

The Emerging Role of Presepsin (P-SEP) in the Diagnosis of Sepsis in the Critically Ill Infant: A Literature Review

Sepsis causes high rates of morbidity and mortality in NICUs. The estimated incidence varies between 5 and 170 per 1000 births, depending on the social context. In very low birth-weight neonates, the level of mortality increases with the duration of hospitalization, reaching 36% among infants aged 8–14 days and 52% among infants aged 15–28 days. Early diagnosis is the only tool to improve the poor prognosis of neonatal sepsis. Blood culture, the gold standard for diagnosis, is time-consuming and poorly sensitive. C-reactive protein and procalcitonin, currently used as sepsis biomarkers, are influenced by several maternal and fetal pro-inflammatory conditions in the perinatal age. Presepsin is the N-terminal fragment of soluble CD14 subtype (sCD14-ST): it is released in the bloodstream by monocytes and macrophages, in response to bacterial invasion. Presepsin seems to be a new, promising biomarker for the early diagnosis of sepsis in neonates as it is not modified by perinatal confounding inflammatory factors. The aim of the present review is to collect current knowledge about the role of presepsin in critically ill neonates.     

Ammonium Formate-Pd/C as a New Reducing System for 1,2,4-Oxadiazoles. Synthesis of Guanidine Derivatives and Reductive Rearrangement to Quinazolin-4-Ones with Potential Anti-Diabetic Activity

1,2,4-Oxadiazole is a heterocycle with wide reactivity and many useful applications. The reactive O-N bond is usually reduced using molecular hydrogen to obtain amidine derivatives. NH₄CO₂H-Pd/C is here demonstrated as a new system for the O-N reduction, allowing us to obtain differently substituted acylamidine, acylguanidine and diacylguanidine derivatives. The proposed system is also effective for the achievement of a reductive rearrangement of 5-(2′-aminophenyl)-1,2,4-oxadiazoles into 1-alkylquinazolin-4(1H)-ones. The alkaloid glycosine was also obtained with this method. The obtained compounds were preliminarily tested for their biological activity in terms of their cytotoxicity, induced oxidative stress, α-glucosidase and DPP4 inhibition, showing potential application as anti-diabetics.     

Capillary extrusion behavior of phenolphthalein poly(ether-ether-sulphone) (PES-C)

The capillary extrusion flow properties of novel engineering thermoplastic phenolphthalein poly(ether-ether-sulphone) (PES-C) have been investigated using capillary rheometer. The dependence of viscosity on the wall shear rate and temperatures were obtained. The flow activation energy was found to decrease with shear rate but to be constant with shear stress. The entrance effect was calculated and from which the extensional behavior was estimated using Cogswell's method. From the extrudate swell ratio the principal normal stress was evaluated and a temperature-independent correlation was observed when they were plotted against shear stress. The melt fracture phenomena were checked and discussed also. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:951–958, 1997     

Rapid and Sensitive Detection of Staphylococcus aureus in Food Using Selective Enrichment and Real-Time PCR Targeting a New Gene Marker

Staphylococcus aureus is a bacterial pathogen considered a principal etiological agent of food poisoning. The aim of this study was to develop and evaluate a rapid and sensitive method for the detection of S. aureus in food by using selective enrichment and a new species-specific real-time polymerase chain reaction (PCR). Specific primers and a TaqMan probe targeted to specific S. aureus gene encoding for acriflavine resistance protein were designed. The real-time PCR was highly specific for S. aureus with 100% inclusivity and 100% exclusivity determined using 83 S. aureus strains and 64 non-S.-aureus strains. PCR detection limit of 6.8 × 10¹ and 3.4 × 10¹ CFU ml⁻¹ were obtained with 100% and 70% detection probability, respectively. The single selective enrichment based on the study of different enrichment conditions was selected and a lysis by boiling was used to obtain bacterial DNA. Out of 112 food samples analyzed, 61 were positive by the PCR-based method and 53 by the standard method. Out of ten food matrices artificially contaminated at a level of 10° CFU g⁻¹, ten and six were positive by the respective methods. Moreover, 10° CFU 10 g⁻¹ was detected in all ten artificially contaminated samples after a large-scale enrichment using PCR-based detection, in contrast to seven false negative by standard detection. The developed method facilitated the detection of S. aureus on the next day after the sample reception. This method can be used for S. aureus detection as a faster, highly specific, and more sensitive alternative to microbiological method with the potential for providing of improved food-processing hygiene control.     

Colorectal Cancer Apoptosis Induced by Dietary δ-Valerobetaine Involves PINK1/Parkin Dependent-Mitophagy and SIRT3

Understanding the mechanisms of colorectal cancer progression is crucial in the setting of strategies for its prevention. δ-Valerobetaine (δVB) is an emerging dietary metabolite showing cytotoxic activity in colon cancer cells via autophagy and apoptosis. Here, we aimed to deepen current knowledge on the mechanism of δVB-induced colon cancer cell death by investigating the apoptotic cascade in colorectal adenocarcinoma SW480 and SW620 cells and evaluating the molecular players of mitochondrial dysfunction. Results indicated that δVB reduced cell viability in a time-dependent manner, reaching IC50 after 72 h of incubation with δVB 1.5 mM, and caused a G2/M cell cycle arrest with upregulation of cyclin A and cyclin B protein levels. The increased apoptotic cell rate occurred via caspase-3 activation with a concomitant loss in mitochondrial membrane potential and SIRT3 downregulation. Functional studies indicated that δVB activated mitochondrial apoptosis through PINK1/Parkin pathways, as upregulation of PINK1, Parkin, and LC3B protein levels was observed (p < 0.0001). Together, these findings support a critical role of PINK1/Parkin-mediated mitophagy in mitochondrial dysfunction and apoptosis induced by δVB in SW480 and SW620 colon cancer cells.