A New Expression for the Gain-Noise Relation of Single-Carrier Avalanche Photodiodes With Arbitrary Staircase Multiplication Regions

We propose a simple expression to relate the total excess noise factor of a single-carrier multiplication staircase avalanche photodiode (APD) to the excess noise factor and gain given by the individual conduction band discontinuities. The formula is valid when electron impact ionization dominates hole impact ionization; hence, it is especially suited for staircase APDs with In-rich multiplication regions, as opposed, for example, to GaAs/AlGaAs systems where hole ionization plays an important role. The formula has been verified by accurate means of numerical simulations based on a newly developed nonlocal history dependent impact ionization model

Experimental and simulation analysis of carrier lifetimes in GaAs/AlGaAs Avalanche Photo-Diodes

Extensive experimental characterization and TCAD simulation analysis have been used to study the dark current in Avalanche Photo-Diodes (APDs). The comparison between the temperature dependence of measurements and simulations points out that SRH generation/recombination is responsible for the observed dark current. After the extraction of the carrier lifetimes in the GaAs layers, they have been used to predict the APD collection efficiency of the photo-generated currents under realistic operation conditions and as a function of the photogeneration position inside the absorption layer

Optimization of GaAs/AlGaAs staircase avalanche photodiodes accounting for both electron and hole impact ionization

A recently developed nonlocal history dependent model for electron and hole impact ionization is used to compute the gain and the excess noise factor in avalanche photodiodes featuring heterojunctions of III-V compound semiconductors while accounting for both carriers. The model has been calibrated with measurements by our group, as well as on noise versus gain data from the literature. We explore the avalanche photodiode design trade-offs related to the number of GaAs/AlGaAs conduction band steps for X-ray spectroscopy applications

Pharmacogenomic evaluation of single nucleotide polymorphisms associated with oxaliplatin-induced peripheral neuropathy: a preliminary study

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Comparative Effectiveness of Gemcitabine plus Nab-Paclitaxel and FOLFIRINOX in the First-Line Setting of Metastatic Pancreatic Cancer: A Systematic Review and Meta-Analysis

Gemcitabine and nab-paclitaxel (GEM-NAB) and the combination of 5-fluorouracil, oxaliplatin, and irinotecan (FOLFIRINOX) are valid first-line options for advanced or metastatic pancreatic cancer (mPC). However, no randomized trials comparing the two schemes have been performed. This meta-analysis aims to compare GEM-NAB and FOLFIRINOX in terms of safety and effectiveness, taking into account data from real-life studies on mPC. We systematically searched PubMed, EMBASE and Cochrane library up to November 2018 to identify retrospective or cohort studies on mPC comparing GEM-NAB and FOLFIRINOX. We included 16 retrospective studies, including 3813 patients (2123 treated with GEM-NAB and 1690 treated with FOLFIRINOX). Despite a median weighted overall survival (OS) difference in favor of FOLFIRINOX (mean difference: 1.15, 95% confidence interval CI 0.08\u207b2.22, p = 0.03), in whole population OS was similar (hazard ratio (HR = 0.99, 95% CI 0.84\u207b1.16; p = 0.9). PFS was also not different between the two arms (HR = 0.88, 95% CI 0.71\u207b1.1; p = 0.26). The overall response rate was similar (25 vs. 24% with GEM-NAB and FOLFIRINOX). Among grade 3\u207b4 toxicities, neutropenia, febrile neutropenia, and nausea were lower with GEM-NAB, while neurotoxicity and anemia were lower with FOLFIRINOX. In conclusion, despite a numerically longer median OS with FOLFIRINOX as compared to GEM-NAB, the overall risk of death and progression were similar. Their toxicity was different with less nausea, neutropenia, and febrile neutropenia with GEM-NAB, as compared to less neurotoxicity and anemia with FOLFIRINOX. Therefore, analysis of non-randomized "real world" studies to date has not provided evidence of a major benefit of one regimen over the other

Volatile organic compounds as biomarkers of gastrointestinal diseases and nutritional status

Purpose. The purpose of this review was to identify the best solution for rapid and noninvasive diagnosis and long-term monitoring of patients affected by inflammatory gastrointestinal diseases, colon and gastric cancer, obesity in correlation to diet, and breast milk to evaluate exposure to VOCs in women and infants. Methods. This review included 20 previously published eligible studies. VOC analysis has allowed us to highlight differences in lifestyles, intestinal microbiota, and metabolism. New innovative methods have been described that allow the detection and quantification of a broad spectrum of metabolites present in exhaled breath even at very low levels, some of which have been shown to be indicators of pathological conditions. Results. Five studies were analyzed that involved VOC analysis in relation to type of diet. All of them showed that the type of diet can have an impact on metabolites excreted and therefore can be a useful tool in the nutritional studies related to metabolism and health and disease status. Two studies concerned VOC analysis in inflammatory bowel diseases, and the results showed that VOCs can distinguish active disease from remission; VOC profile is clearly different in patients. In particular, C15H30 1-pentadecene, 3-methyl-1-butanal, octane, acetic acid, alpha-pinene, and m-cymene are elevated in active ulcerative colitis. Four studies examined VOCs in gastric and colorectal tumors showing a change in metabolic biomarkers of cancer patients compared to the control group. Finally, the study of VOCs in breast milk has improved the understanding of the potential health risks of exposure of children to chemical pollutants. Conclusions. VOC analysis allowed to highlight differences in behavior, lifestyle, and metabolism of individuals. Analytical methods are continuously developed to allow for better detection and quantification of metabolites, thus enabling the detection of a broader spectrum of pathophysiology and disease biomarkers

Modeling Approaches for Gain, Noise and Time Response of Avalanche Photodiodes for X-Rays Detection

We report on a suite of modeling approaches for the optimization of Avalanche Photodiodes for X-rays detection. Gain and excess noise are computed efficiently using a non-local/history dependent model that has been validated against full-band Monte Carlo simulations. The (stochastic) response of the detector to photon pulses is computed using an improved Random-Path-Length algorithm. As case studies, we consider diodes consisting of AlGaAs/GaAs multi-layers with separated absorption and multiplication regions. A superlattice creating a staircase conduction band structure is employed in the multiplication region to keep the multiplication noise low. Gain and excess noise have been measured in devices fabricated with such structure and successfully compared with the developed models

Clinical trials on pain lowering effect of ginger: A narrative review

Ginger has a pain-reducing effect and it can modulate pain through various mechanisms: inhibition of prostaglandins via the COX and LOX-pathways, antioxidant activity, inibition of the transcription factor nf–kB, or acting as agonist of vanilloid nociceptor. This narrative review summarizes the last 10-year of randomized controlled trials (RCTs), in which ginger was traditionally used as a pain reliever for dysmenorrhea, delayed onset muscle soreness (DOMS), osteoarthritis (AO), chronic low back pain (CLBP), and migraine. Regarding dysmenorrhea, six eligible studies suggest a promising effect of oral ginger. As concerned with DOMS, the four eligible RCTs suggested a reduction of inflammation after oral and topical ginger administration. Regarding knee AO, nine RCTs agree in stating that oral and topical use of ginger seems to be effective against pain, while other did not find significant differences. One RCT considered the use of ginger in migraine and suggested its beneficial activity. Finally, one RCT evaluated the effects of Swedish massage with aromatic ginger oil on CLBP demonstrated a reduction in pain. The use of ginger for its pain lowering effect is safe and promising, even though more studies are needed to create a consensus about the dosage of ginger useful for long-term therapy

Clinical implications for pro-GRP in small cell lung cancer. A single center experience

Recently, pro-gastrin-releasing peptide (pro-GRP) became available as an alternative sensitive, specific and reliable tumor marker for patients with small cell lung cancer (SCLC), both in limited (LD) and diffuse disease (DD)

Systemic Treatment of Patients With Gastrointestinal Cancers During the COVID-19 Outbreak: COVID-19-adapted Recommendations of the National Cancer Institute of Milan

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak poses a major challenge in the treatment decision-making of patients with cancer, who may be at higher risk of developing a severe and deadly SARS-CoV-2 infection compared with the general population. The health care emergency is forcing the reshaping of the daily assessment between risks and benefits expected from the administration of immune-suppressive and potentially toxic treatments. To guide our clinical decisions at the National Cancer Institute of Milan (Lombardy region, the epicenter of the outbreak in Italy), we formulated Coronavirus-adapted institutional recommendations for the systemic treatment of patients with gastrointestinal cancers. Here, we describe how our daily clinical practice has changed due to the pandemic outbreak, with the aim of providing useful suggestions for physicians that are facing the same challenges worldwide