Angular momentum transfer from swift electrons to non-spherical nanoparticles within the dipolar approximation.

In this work, we study the angular momentum transfer from a single swift electron to non-spherical metallic nanoparticles, specifically investigating spheroidal and polyhedral (Platonic Solids) shapes. While previous research has predominantly focused on spherical nanoparticles, our work expands the knowledge by exploring various geometries. Employing classical electrodynamics and the small particle limit, we calculate the angular momentum transfer by integrating the spectral density, ensuring causality through Fourier-transform analysis. Our findings demonstrate that prolate spheroidal nanoparticles exhibit a single blueshifted plasmonic resonance, compared to spherical nanoparticles of equivalent volume, resulting in lower angular momentum transfer. Conversely, oblate nanoparticles display two resonances - one blueshifted and one redshifted - resulting in a higher angular momentum transfer than their spherical counterparts. Additionally, Platonic Solids with fewer faces exhibit significant redshifts in plasmonic resonances, leading to higher angular momentum transfer due to edge effects. We also observe resonances and angular momentum transfers with similar characteristics in specific pairs of Platonic Solids, known as duals. These results highlight promising applications, particularly in electron tweezers technology.

Low-dose rituximab in steroid-refractory chronic graft-versus-host disease.

BACKGROUND: Chronic graft-versus-host disease (cGvHD) is a major complication that puts patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at risk of death or infection. Currently, there is no gold standard for the first-line treatment of patients who do not respond to steroids, and there are several therapeutic options being evaluated in clinical trials for this disease to be used even in the first-line treatment for GvHD. There is evidence of the benefit of rituximab, an anti-CD20 antibody, at a standard dose of 375 mg/m2 weekly in the treatment of steroid-refractory chronic graft-versus disease (SR-cGvHD). OBJECTIVE: To demonstrate the safety and efficacy of low-dose rituximab in a middle-income center in northeastern Mexico STUDY DESIGN: We report the experience of 26 patients with chronic graft-versus-graft disease who received low-dose rituximab (100 mg weekly for 4 weeks). We utilized the advances in the National Institutes of Health (NIH) criteria for diagnosis, scoring, trial design, and assessment of treatment response. RESULTS: We obtained a 5-year overall survival of 23.6%, including four patients with complete response. The 1-year event-free survival was 70% for patients with rituximab. During the treatment, there were 3 hospitalizations, and the causes were: immune thrombocytopenia, a parapneumonic effusion, and a cerebral vascular event. The median length of hospital stay was twelve days. CONCLUSION: A low dose of rituximab is an available and cost-effective option for patients with steroid-refractory cGvHD.

Carcinoid Heart Disease From a Primary Liver Carcinoid Tumor.

Carcinoid heart disease (CaHD) is part of the carcinoid syndrome. Cardiac involvement is present in 20% to 60% of patients with carcinoid syndrome and is normally from liver metastasis. We report the case of a patient who presented with CaHD disease with an undiagnosed primary tumor or a possible primary liver carcinoid tumor. (Level of Difficulty: Advanced.).

Complete Genome Sequences of the Novel Cluster BP Phages Infecting Streptomyces sanglieri, AxeJC, Cumberbatch, Eastland, Eklok, HFrancette, Ignacio, Piccadilly, and Vondra.

The Streptomyces sanglieri bacteriophages AxeJC, Cumberbatch, Eastland, Eklok, HFrancette, Ignacio, Piccadilly, and Vondra form a novel actinobacteriophage cluster, BP. These siphoviruses have circularly permuted genomes with an average size of 37,700 bp and a GC content of 71%. Each genome contains approximately 58 protein-coding genes, with no tRNAs.

Angular dynamics of small nanoparticles induced by non-vortex electron beams.

In this work, we present a theoretical study of the angular dynamics of small nanoparticles induced by fast non-vortex electron beams. General expressions for the torque and the angular momentum transferred from an electron to an arbitrary-but small-nanoparticle are obtained using a full-retarded classical electrodynamics approach, within the small particle limit. We applied this methodology to study a particular case of interest: the angular dynamics of spherical nanoparticles with homogeneous and isotropic electromagnetic responses. We analytically calculate the total angular momentum transferred from a swift electron to such nanoparticles, finding that it is electric in nature and it is always in a direction determined by the electron trajectory relative to the center of the nanoparticle. We realize that it is possible to represent the angular momentum transferred as the product of two functions: the extinction cross-section of the nanoparticle and a function that only contains information about the swift electron. We present numerical results for the total angular momentum transferred from a swift electron to an aluminum and a gold nanoparticle. We also present an analysis of the temporal behavior of the torque and the electric dipole moment induced within the nanoparticle by the swift electron. We compare the angular momentum transfer calculated in this work with a previously reported case of vortex beams, finding that, for both aluminum and gold nanoparticles, our results are two orders of magnitude smaller. Finally, we consider a particular case of a frictionless gold spherical nanoparticle of radius a=5nm, obtaining that it can spin with an angular frequency up to 29.3Hz.

Predictive markers of nonalcoholic fatty liver disease in lean patients. A multinomial regression model and a 2k factorial analysis.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and insulin resistance; however, there is a group of non-obese patients with NAFLD that need to be characterized. Our aim was to evaluate the factors associated with NAFLD in non-obese subjects in a third-level hospital. METHODS: A comparative cross-sectional study was performed. Participants were divided into four groups: non-obese without NAFLD (group 1), non-obese with NAFLD (group 2), obese without NAFLD (group 3), and obese with NAFLD (group 4). We evaluated the effect of clinical and biochemical characteristics with the disease by groups using a multinomial regression model and a 2K factorial analysis. RESULTS: We included 278 participants. Low platelet-lymphocyte ratio (PLR) as a novel parameter associated with NAFLD in non-obese subjects. Age, uric acid, alanine transaminase (ALT), high-density lipoprotein (HDL)-cholesterol, and neutrophil-lymphocyte ratio (NLR) were other related parameters (akaike information criterion = 557). NLR had the larger OR in groups with NAFLD (lean with NAFLD 7.12, obese with NAFLD 13.02). The 2k factorial design found inverse effect on PLR by NAFLD (effect -21.89, P < 0.001), which was higher than BMI (effect -1.33, P < 0.045). CONCLUSION: Our study found that PLR is a novel parameter with inverse correlation with NAFLD in non-obese patients. Other related parameters are age, hyperuricemia, elevation of ALT and NLR, and low HDL-cholesterol.

Dyslipidemia as a risk factor for liver fibrosis progression in a multicentric population with non-alcoholic steatohepatitis.

Background: Nonalcoholic fatty liver disease (NAFLD) is a serious worldwide health problem, with an estimated global prevalence of 24%; it has a notable relationship with other metabolic disorders, like obesity and type 2 diabetes mellitus (T2DM). Nonalcoholic steatohepatitis (NASH) is one of the most important clinical entities of NAFLD, which is associated with an increased risk of progression to liver cirrhosis and hepatocellular carcinoma (HCC). Mexico is one of the countries with the highest prevalence of metabolic diseases; therefore, we sought to investigate the impact that these clinical entities have in the progression to advanced fibrosis in Mexican patients with NASH. Methods: We performed a multicenter retrospective cross-sectional study, from January 2012 to December 2017. A total of 215 patients with biopsy-proven NASH and fibrosis were enrolled. NASH was diagnosed according NAS score and liver fibrosis was staged by the Kleiner scoring system. For comparing the risk of liver fibrosis progression, we divided our sample into two groups. Those patients with stage F0-F2 liver fibrosis were included in the group with non-significant liver fibrosis (n=178) and those individuals with F3-F4 fibrosis were included in the significant fibrosis group (n=37). We carried out a multivariate analysis to find risk factors associated with liver fibrosis progression. Results: From the 215 patients included, 37 had significant liver fibrosis (F3-4). After logistic regression analysis T2DM (p=0.044), systemic arterial hypertension (p=0.014), cholesterol (p=0.041) and triglycerides (p=0.015) were the main predictor of advanced liver fibrosis. Conclusions: In a Mexican population, dyslipidemia was the most important risk factor associated with advanced liver fibrosis and cirrhosis.

Current trends of liver cirrhosis in Mexico: Similitudes and differences with other world regions.

AIM: To investigate the main current etiologies of cirrhosis in Mexico. METHODS: We performed a cross-sectional retrospective multicenter study that included eight hospitals in different areas of Mexico. These hospitals provide health care to people of diverse social classes. The inclusion criteria were a histological, clinical, biochemical, endoscopic, or imaging diagnosis of liver cirrhosis. Data were obtained during a 5-year period (January 2012-December 2017). RESULTS: A total of 1210 patients were included. The mean age was 62.5 years (SD = 12.1), and the percentages of men and women were similar (52.0% vs 48.0%). The most frequent causes of liver cirrhosis were hepatitis C virus (HCV) (36.2%), alcoholic liver disease (ALD) (31.2%), and nonalcoholic steatohepatitis (23.2%), and the least frequent were hepatitis B virus (1.1%), autoimmune disorders (7.3%), and other conditions (1.0%). CONCLUSION: HCV and ALD are the most frequent causes of cirrhosis in Mexico. However, we note that non-alcoholic fatty liver disease (NAFLD) as an etiology of cirrhosis increased by 100% compared with the rate noted previously. We conclude that NAFLD will soon become one of the most frequent etiologies of liver cirrhosis in Mexico.

Linfoma de la zona gris con características intermedias entre un linfoma difuso de células B grandes y un linfoma Hodgkin clásico. Reporte de un caso y revisión de la literatura / Grey zone lymphoma with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma. Case report and literature review

Resumen Entre los linfomas de la zona gris (LZG) encontramos neoplasias con características compartidas entre un linfoma difuso de células B grandes (LDCBG) y un linfoma de Hodgkin clásico (LHC). Lo poco habitual de la patología combinado con la heterogenicidad de la enfermedad, su reciente descripción como entidad específica que conlleva a dificultad y reto diagnóstico, así como la falta de suficiente experiencia terapéutica hacen de la enfermedad una entidad compleja de difícil diagnóstico y reto terapéutico que justifica su descripción continua. Se presenta una paciente con fiebre de un mes sin respuesta al manejo inicial, se estudió y realizó biopsia de ganglio inguinal izquierdo con resultado diagnóstico de LZG con características intermedias entre LDCBG y LHC. Aunque no existen guías establecidas para el manejo de esta entidad, la evidencia actual sugiere mejor respuesta en tratamientos dirigidos a LDCBG, misma terapia empleada en esta paciente con la cual se obtuvo respuesta favorable.

Abstract In the grey zone lymphomas (GZL), there are overlapping characteristics between diffuse large B-cell lymphoma (DLBCL) and classic Hodgkin lymphoma (CHL). The unusual nature of the pathology combined with the heterogeneity of the disease, its recent description as a specific entity, its diagnostic difficulty, and the lack of sufficient therapeutic experience justifies its continuous description. The case is presented of a patient with a fever of one month onset, with no response to initial management. A left inguinal lymph node biopsy reported a diagnosis of GZL with intermediate characteristics between DLBCL and CHL. Although there are no established guidelines for the management of this condition, the current evidence suggests a better response in treatments meant for diffuse large B-cell lymphoma. This same therapy was used in this patient, with a favourable clinical outcome.

Analysis of electromagnetic forces and causality in electron microscopy.

The non-physical effects on the transverse momentum transfer from fast electrons to gold nanoparticles associated to the use of non-causal dielectric functions are studied. A direct test of the causality based on the surface Kramers-Kronig relations is presented. This test is applied to the different dielectric function used to describe gold nanostructures in electron microscopy.

Analytical modeling of optical reflectivity of random plasmonic nano-monolayers.

In this paper, we compare three different models that have been used to interpret reflectivity measurements of supported monolayers of nanoparticles. Two of them: (i) isotropic Maxwell Garnett and (ii) anisotropic two-dimensional-dipolar model are based on an effective-medium approach, while the third one (iii) coherent-scattering model, lies within the framework of multiple-scattering theory. First, we briefly review, on physical grounds, the foundations of each model and write down the corresponding formulas for the calculation of the reflectivity. In the two-dimensional-dipolar model, the dilute limit of the pair-correlation function (also called hole-correlation function) is always used in the calculation of the effective optical response. Then we use these formulas to plot and analyze graphs of the reflectivity of a monolayer of gold nanoparticles on a glass substrate, as a function of several relevant parameters, for two different commonly used experimental configurations. Finally, we discuss the importance of our results and how they can be used to infer the limits of validity of each model.

Surface enhanced Raman scattering of amino acids assisted by gold nanoparticles and Gd(3+) ions.

The surface enhanced raman scattering (SERS) signal from the l-tyrosine (tyr) molecule adsorbed on gold nanoparticles (Au-tyr) is compared with the SERS signal assisted by the presence of gadolinium ions (Gd(3+)) coordinated with the Au-tyr system. An enhancement factor of the SERS signal in the presence of Gd(3+) ions was ∼5 times higher than that produced by l-tyrosine adsorbed on gold nanoparticles. The enhancement of the SERS signal can be attributed to a corresponding increase in the local electric field due to the presence of Gd(3+) ions in the vicinity of a gold dimer configuration. This scenario was confirmed by solving numerically Maxwell equations, showing an increase of 1 order of magnitude in the local electric scattered field when the Gd(3+) ion is located in between a gold dimer compared with naked gold nanoparticles.

Multipolar plasmon resonances in individual ag nanorice.

We study the optical excitation of high-order surface plasmon resonance modes in individual Ag nanorice particles using dark-field scattering spectroscopy. We analyze the results by model calculations using the boundary element method. Symmetry breaking caused by oblique illumination makes the even order resonance modes observable in the optical spectrum. All the resonance peaks are found to redshift with increasing length of the particle.

Coherent reflection of light from a turbid suspension of particles in an internal-reflection configuration: Theory versus experiment.

We compare a recently developed coherent-scattering model for the reflectance of light from a turbid colloidal suspension of particles with experimental measurements. The experimental data were obtained in an internal reflection configuration around the critical angle using a glass prism in contact with a monodisperse colloidal suspension of latex particles, and a polydisperse suspension of TiO2 particles. First, we review the coherent scattering model and extend it to the case of polydisperse suspensions in an internal reflection configuration. The experimental data is then compared with results of the coherent scattering model and results obtained assuming that the colloidal system can be treated as a homogeneous medium with an effective index of refraction. We find that the experimental results are not compatible with the effective medium model. On the other hand, good fits to the experimental curves can be obtained with the coherent scattering model.