Evaluation of the Performance of Atomic Diffusion Additive Manufacturing Electrodes in Electrical Discharge Machining

Atomic Diffusion Additive Manufacturing (ADAM) is an innovative Additive Manufacturing process that allows the manufacture of complex parts in metallic material, such as copper among others, which provides new opportunities in Rapid Tooling. This work presents the development of a copper electrode manufactured with ADAM technology for Electrical Discharge Machining (EDM) and its performance compared to a conventional electrolytic copper. Density, electrical conductivity and energy-dispersive X-ray spectroscopy were performed for an initial analysis of both ADAM and electrolytic electrodes. Previously designed EDM experiments and optimizations using genetic algorithms were carried out to establish a comparative framework for both electrodes. Subsequently, the final EDM tests were carried out to evaluate the electrode wear rate, the roughness of the workpiece and the rate of material removal for both electrodes. The EDM results show that ADAM technology enables the manufacturing of functional EDM electrodes with similar material removal rates and rough workpiece finishes to conventional electrodes, but with greater electrode wear, mainly due to internal porosity, voids and other defects observed with field emission scanning electron microscopy.     

Visible and Quantifiable Improvement in Skin Roughness and Texture Using a High Power Non-ablative 1540-nm Fractional Erbium: Glass Laser

BackgroundNon-ablative fractional laser treatments for improving skin tone and rejuvenation have become increasingly popular due to short downtime and fewer side effects compared to ablative treatments.Objective We sought to determine the efficacy of a non-ablative 1540-nm fractional erbium: glass laser in improving skin roughness and skin texture.MethodsThe forehead, cheek, and nasal areas of 15 patients were treated for five monthly sessions using a 7x7 pixel tip (1.21cm² affective area, approximately 300 microns diameter per pixel), fluence of 2,500 to 3,000 mJ/pulse (40–62 mJ/Pixel), and three stacked pulses were emitted at a rate of 1Hz for three passes per treatment session. Measurements of skin roughness, skin roughness area, and maximum skin depth were collected using a 3D imaging system. Improvement in skin parameters was calculated by comparing the measurements prior to treatment and 12 weeks after completion.ResultsAll 15 patients showed significant improvement in all three measured parameters (p<0.001) with no significant side effects.LimitationsThe limitations of this study include the small number of patients and the narrow range of skin tone (Fitzpatrick Skin Types II–IV).ConclusionOur results suggest that monthly treatments with a non-ablative 1540-nm fractional Erbium:glass laser appear to be safe and effective for skin texture and roughness.     

Association between Adherence to the Mediterranean Diet and Anthropometric and Health Variables in College-Aged Males

The present study aimed to verify the association between adherence to the Mediterranean diet (MD) and anthropometric and health variables. Four-hundred-and-ninety-five college-aged males aged 18–25 participated in this cross-sectional research. The KIMED (Mediterranean Diet Quality Index for children and adolescents) was used to assess the adherence to MD. The following variables were also assessed: body mass (BM), height (HE), body mass index (BMI), body fat percentage (%FAT), lean mass (LEAN), abdominal girth (AG), waist-to-hip ratio (WHR), oxygen saturation (SPO2), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), and fasting blood glucose (GLU). The results showed that adherence to MD presented a strong negative correlation with most of the anthropometric parameters (BM: r = −0.571; BMI: r = −0.614; %FAT: r = −0.558; and AG: r = −0.564), a moderate or weak correlation with most of the health variables (GLU: r = −0.407; SBP: r = −0.238; DBP: r = −0.217, and DP: r = −0.265) and LEAN (r = −0.497), and a very weak correlation with WHR (r = −0.090). Many anthropometric parameters (BM, BMI, %FAT, LEAN, AG, WHR) present significant correlations with health variables (SBP, DBP, DP, and GLU). We conclude that greater adherence to Mediterranean diet is associated with healthier values of the selected anthropometric and health parameters. Since most of the anthropometric and health parameters present significant correlations among themselves, this finding could be useful in medical diagnosis, health monitoring, and risk detection. Based on the level of adherence to Mediterranean diet and the KIDMED found in the present study, and considering the prevalence of obesity in the Middle East, it is imperative to implement nutritional interventions with the target population of this research to prevent nutrition-related diseases and promote public health.     

Diet and SIRT1 Genotype Interact to Modulate Aging-Related Processes in Patients with Coronary Heart Disease: From the CORDIOPREV Study

We investigated whether long-term consumption of two healthy diets (low-fat (LF) or Mediterranean (Med)) interacts with SIRT1 genotypes to modulate aging-related processes such as leucocyte telomere length (LTL), oxidative stress (OxS) and inflammation in patients with coronary heart disease (CHD). LTL, inflammation, OxS markers (at baseline and after 4 years of follow-up) and SIRT1-Single Nucleotide Polymorphisms (SNPs) (rs7069102 and rs1885472) were determined in patients from the CORDIOPREV study. We analyzed the genotype-marker interactions and the effect of diet on these interactions. Regardless of the diet, we observed LTL maintenance in GG-carriers for the rs7069102, in contrast to carriers of the minor C allele, where it decreased after follow-up (p = 0.001). The GG-carriers showed an increase in reduced/oxidized glutathione (GSH/GSSG) ratio (p = 0.003), lower lipid peroxidation products (LPO) levels (p < 0.001) and a greater decrease in tumor necrosis factor-alpha (TNF-α) levels (p < 0.001) after follow-up. After the LF diet intervention, the GG-carriers showed stabilization in LTL which was significant compared to the C allele subjects (p = 0.037), although the protective effects found for inflammation and OxS markers remained significant after follow-up with the two diets. Patients who are homozygous for the SIRT1-SNP rs7069102 (the most common genotype) may benefit from healthy diets, as suggested by improvements in OxS and inflammation in patients with CHD, which may indicate the slowing-down of the aging process and its related diseases.     

Improved control of SARS-CoV-2 by treatment with a nucleocapsid-specific monoclonal antibody

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main antigen in all approved COVID-19 vaccines and is also the only target for monoclonal antibody (mAb) therapies. Immune responses to other viral antigens are generated after SARS-CoV-2 infection, but their contribution to the antiviral response remains unclear. Here, we interrogated whether nucleocapsid-specific antibodies can improve protection against SARS-CoV-2. We first immunized mice with a nucleocapsid-based vaccine and then transferred sera from these mice into naive mice, followed by challenge with SARS-CoV-2. We show that mice that received nucleocapsid-specific sera or a nucleocapsid-specific mAb exhibited enhanced control of SARS-CoV-2. Nucleocapsid-specific antibodies elicited NK-mediated, antibody-dependent cellular cytotoxicity (ADCC) against infected cells. To our knowledge, these findings provide the first demonstration in the coronavirus literature that antibody responses specific to the nucleocapsid protein can improve viral clearance, providing a rationale for the clinical evaluation of nucleocapsid-based mAb therapies to treat COVID-19.     

Effect of peripheral refractive errors on driving performance

The effect of peripheral refractive errors on driving while performing secondary tasks at 40° of eccentricity was studied in thirty-one young drivers. They drove a driving simulator under 7 different induced peripheral refractive errors (baseline (0D), spherical lenses of +/- 2D, +/- 4D and cylindrical lenses of +2D and +4D). Peripheral visual acuity and contrast sensitivity were also evaluated at 40°. Driving performance was significantly impaired by the addition of myopic defocus (4D) and astigmatism (4D). Worse driving significantly correlated with worse contrast sensitivity for the route in general, but also with worse visual acuity when participants interacted with the secondary task. Induced peripheral refractive errors may negatively impact driving when performing secondary tasks.     

Neural networks to identify multiple sclerosis with optical coherence tomography

Purpose:  To compare axonal loss in ganglion cells detected with spectral‐domain optical coherence tomography (OCT) in eyes of patients with multiple sclerosis (MS) versus healthy control subjects using an artificial neural network (ANN). To analyse the capability of the ANN technique to improve the detection of retinal nerve fibre layer (RNFL) damage in patients with multiple sclerosis. Methods:  Patients with multiple sclerosis (n = 106) and age‐matched healthy subjects (n = 115) were enrolled. The Spectralis OCT system was used to obtain the circumpapillary RNFL thickness in both eyes. The 768 RNFL thickness measurements provided by the Spectralis OCT were performed to obtain thickness measurements from 24 uniformly divided locations around the peripapillary RNFL. The performance of the ANN technique for identifying RNFL loss in patients with multiple sclerosis was evaluated. Receiver‐operating characteristic (ROC) curves were used to display the ability of the test to discriminate between MS and healthy eyes in our population. ROC curves obtained using ANN and parameters provided by OCT (mean and 6 sector thicknesses) were compared. Results:  The capability of the ANN technique to detect RNFL loss in patients with multiple sclerosis compared with healthy subjects was good. The area under the ROC curve was 0.945. Compared with the OCT‐provided parameters, the ANN had the largest area under the ROC curve. Conclusions:  Measurements of RNFL thickness obtained with Spectralis OCT have a good ability to differentiate between healthy and individuals with multiple sclerosis. Based on the area under the ROC curve, the ANN performed better than any single OCT parameter.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Clathrin mediates both internalization and vesicular release of triggered T cell receptor at the immunological synapse

Ligation of T cell receptor (TCR) to peptide–MHC (pMHC) complexes initiates signaling leading to T cell activation and TCR ubiquitination. Ubiquitinated TCR is then either internalized by the T cell or released toward the antigen-presenting cell (APC) in extracellular vesicles. How these distinct fates are orchestrated is unknown. Here, we show that clathrin is first recruited to TCR microclusters by HRS and STAM2 to initiate release of TCR in extracellular vesicles through clathrin- and ESCRT-mediated ectocytosis directly from the plasma membrane. Subsequently, EPN1 recruits clathrin to remaining TCR microclusters to enable trans-endocytosis of pMHC–TCR conjugates from the APC. With these results, we demonstrate how clathrin governs bidirectional membrane exchange at the immunological synapse through two topologically opposite processes coordinated by the sequential recruitment of ecto- and endocytic adaptors. This provides a scaffold for direct two-way communication between T cells and APCs.

The fundamental molecular interactions responsible for regulating the adaptive immune response occur within a nanoscale gap between T cells and antigen-presenting cells (APCs) termed the immunological synapse (IS). IS formation is induced upon T cell receptor (TCR) interactions with agonist peptide-Major Histocompatibility Complex (pMHC) on the surface of APCs (1, 2). This process can be recapitulated by antigen presentation on supported lipid bilayers (SLBs), a minimal system composed of a mobile lipid phase configured to present relevant ligands at physiological densities (3, 4). Such IS formation on SLBs allows for microscopic analysis of the receptor–ligand interactions and membrane trafficking events underlying the initiation and effector functions of the adaptive immune system.During activation, the components of the IS rearrange in the opposing lipid membranes to form a characteristic bull’s-eye pattern consisting of three primary domains (5, 6). The bull’s-eye itself is termed the central supramolecular activation cluster (cSMAC) and is dominated by TCR and its ligands in a synaptic cleft. This area is surrounded by an adhesive ring defined by Lymphocyte Function-associated Antigen-1 (LFA-1) on the T cell side associated with intercellular adhesion molecule-1 (ICAM-1) on the SLB termed the peripheral supramolecular activation cluster (pSMAC). The outer edge of the contact is defined by an F-actin–rich sensory compartment termed the distal supramolecular activation cluster (dSMAC). TCR engagement is initiated in microclusters that arise from filopodia in the dSMAC and retain protrusive activity even as they traffic through the pSMAC toward the cSMAC (7–11). This is accompanied by CD3 tyrosine phosphorylation, recruitment of Zeta-associated protein of 70 kDa (ZAP-70), and phosphorylation of Linker of Activated T cells (LAT) (12) and recruitment of SH2-domain-containing leukocyte protein of 76 kDa (SLP-76) (13). These then form condensates organized by LAT, traversing concentric actin networks en route to the cSMAC (14).Formation of the cSMAC by helper T cells has been shown to require recognition of ubiquitinated TCR by Tumor susceptibility gene 101 (TSG101), a component of the endosomal sorting complex required for transport (ESCRT) (15). Then, following TSG101-dependent TCR sorting, the ESCRT-associated ATPase VPS4 mediates scission of TCR loaded extracellular vesicles termed synaptic ectosomes, which bud directly from the plasma membrane into the synaptic cleft (16). This is mechanistically similar to formation of the intraluminal vesicles (ILVs) of multivesicular endosomes and budding of HIV virions from the plasma membrane (17, 18). Prior to action of TSG101, the ESCRT component Hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) recognizes ubiquitinated cargo and recruits clathrin, which assembles into flat lattices to mediate recruitment of subsequent ESCRT machinery (19, 20). Clathrin- and HRS-positive vesicles have also been shown to polarize toward the IS during T cell activation, and they have been implicated in recruiting F-actin there (21). However, it is not known whether clathrin is involved in the formation of synaptic ectosomes.Clathrin is primarily known for its role in endocytosis, where it is recruited to the plasma membrane by adaptor proteins such as Epsin-1 (EPN1) and Adaptor Protein complex-2 (AP-2) (22, 23). Together, these proteins facilitate deformation and invagination of the membrane which is ultimately pinched off as a clathrin-coated endocytic vesicle (24) by the large GTPase dynamin (25–27). Previous reports have shown that this mechanism is engaged to internalize TCR during constitutive TCR recycling (28, 29) and to internalize nonactivated bystander TCR during T cell activation (30). It has also been shown that TCR triggering leads to phosphorylation of clathrin heavy chain (CHC), (31) and TCR has been observed in clathrin-coated pits following antibody activation (32). However, conflicting evidence has indicated that clathrin is not involved in internalization of triggered TCR in the Jurkat cell line (30, 33, 34). Hence, the role of clathrin in endocytosis of pMHC–TCR conjugates is yet to be established.Synaptic ectosomes are important for delivery of T cell help through CD40 ligand and additional signals (35). TCR endocytosis is required for postendocytic signaling and regulation of pMHC availability (36, 37). Therefore, it is critical to understand the balance between ectocytosis and endocytosis of the TCR. Here, we show that clathrin is pivotal during T cell activation through its essential role in two sequential processes. First, clathrin is essential for ESCRT-mediated release of TCR loaded synaptic ectosomes at the cSMAC. As the IS matures, there is a temporal switch from the clathrin-associated ESCRT components HRS and STAM2 to the endocytic clathrin adaptor EPN1. Remaining antigen-ligated TCRs are then internalized by clathrin-mediated trans-endocytosis.     

Pancreas fat content,insulin homeostasis and circulating endothelial microparticles in male essential hypertensive patients

The pancreas fat content has been poorly investigated in essential hypertension. The authors aim to relate pancreas and liver fat content with parameters measuring insulin resistance, beta‐cell function and also with markers of endothelial dysfunction and platelet or endothelial cell destruction. The authors studied a group of 40 male hypertensive patients with well‐controlled blood pressure, maintaining a stable weight, and having not changed their medication during the last year. Pancreas fat content was correlated with HOMA‐IR (r = .616, p < .001), HOMA‐S (r = −.439, p < .005), beta cell function parameter (r = .457, p < .005), and QUICKI (r = .412, p < .01), whereas liver fat was not patients in the highest quartile of pancreas fat content had more circulating endothelial microparticles than patients in the other quartiles (median 129 [94.3–200] vs. 60.9 [49.4–88.8], p = .002). However, patients in the highest quartile of the pancreas fat content distribution did not differ from the lowest in hyperemic response after ischemia nor circulating platelet microparticles count. Liver fat content was not related to any of the parameters studied. In a multivariate stepwise binary logistic regression analysis (Wald Method) circulating endothelial microparticles remain significantly associated with pancreas fat content after adjusting for confounding factors, such as tobacco, diabetes mellitus, hypercholesterolemia, or metabolic syndrome. Our results reflect that in essential hypertension, pancreas fat content is superior to liver fat to study beta‐cell functionality and insulin resistance. Moreover, the authors described for the first time that pancreas fat content is related to endothelial cell destruction. Further studies are needed to confirm this point.