Laser transfer for circulating tumor cell isolation in liquid biopsy.

75Cancer research has found in the recent years a formidable ally in liquid biopsy, a noninvasive technique that allows the study of circulating tumor cells (CTCs) and biomolecules involved in the dynamics of cancer spread like cell-free nucleid acids or tumor-derived extracellular vesicles. However, single-cell isolation of CTCs with high viability for further genetic, phenotypic, and morphological characterization remains a challenge. We present a new approach for single CTC isolation in enriched blood samples using a liquid laser transfer (LLT) process, adapted from standard laser direct write techniques. In order to completely preserve the cells from direct laser irradiation, we used an ultraviolet laser to produce a blister-actuated laser-induced forward transfer process (BA-LIFT). Using a plasma-treated polyimide layer for blister generation, we completely shield the sample from the incident laser beam. The optical transparency of the polyimide allows direct cell targeting using a simplified optical setup, in which the laser irradiation module, standard imaging, and fluorescence imaging share a common optical path. Peripheral blood mononuclear cells (PBMCs) were identified by fluorescent markers, while target cancer cells remained unstained. As a proof of concept, we were able to isolate single MDA-MB-231 cancer cells using this negative selection process. Unstained target cells were isolated and culture while their DNA was sent for single-cell sequencing (SCS). Our approach appears to be an effective approach to isolate single CTCs, preserving cell characteristics in terms of cell viability and potential for further SCS.

Picosecond Laser Shock Micro-Forming of Stainless Steel: Influence of High-Repetition Pulses on Thermal Effects.

A study of the peen forming of thin stainless steel metal foils (50 µm thick) using a solid-state ps-pulsed laser, emitting at a wavelength of 1064 nm was conducted. The pitch distance between consecutive laser pulses was kept constant by tuning the laser repetition rate from 0.4 to 10 kHz, and subsequently the scanning speed. The induced bending angle and the radius of curvature were used to measure the effect of the treatment. Their dependence on the pulse energy, the treated area, the distance between lines, and the laser repetition rate was studied. High repetition rates do not allow the sample to cool down, affecting the bending to the point of being negligible. An FEM simulation and experiments were carried out to prove that the increase in temperature due to high repetition rate can relax the stresses induced by laser peen treatment, thus preventing bending in the sample.

Predicción del desarrollo de tromboembolia pulmonar en pacientes con infección por SARS-CoV-2 / Prediction of pulmonary embolism in patients with SARS-CoV-2 infection

Objetivo:Pretendemos determinar los factores predictores de enfermedad tromboembólica pulmonar (ETEP) en pacientes con infección por SARS-CoV-2 (COVID-19) atendidos en el servicio de urgencias de un hospital terciario durante la primera ola pandémica.Métodos:Estudio observacional unicéntrico realizado en una cohorte retrospectiva de pacientes con infección confirmada por SARS-CoV-2 (o alta sospecha clínico-radiológica de COVID-19) sometidos a despistaje de ETEP mediante tomografía computarizada de arterias pulmonares (TCAP). Se exploraron los factores predictores de ETEP mediante regresión logística, creándose dos modelos predictivos (sin o con los valores de dímeros-D).Resultados:De un total de 274 TCAP realizados, 70 procedimientos presentaron hallazgos diagnósticos de ETEP, representando una incidencia acumulada del 25,54% (intervalo de confianza [IC] 95%: 20,49-31,14). En el modelo no ajustado por el nivel de dímeros-D, la frecuencia respiratoria >22rpm (odds ratio [OR]: 3,162; IC 95%: 1,627-6,148; p=0,001) y la ausencia de hallazgos sugerentes de COVID-19 en la radiología simple de tórax (OR: 3,869; IC 95%: 0,869-17,225; p=0,076) fueron predictores de ETEP. En el segundo modelo se mantuvo la presencia de taquipnea (OR: 4,967; IC 95%: 2,053-12,018; p<0,001), identificándose además un nivel de dímeros-D>3.000ng/mL (OR: 7,494; IC 95%: 3,038-18,485; p<0,001).Conclusiones:La presencia de taquipnea (>22rpm) y la ausencia de hallazgos radiológicos sugestivos de infección por SARS-CoV-2 en la radiografía simple de tórax, además de los valores de dímero-D>3.000ng/mL, fueron identificados como factores predictores de ETEP en pacientes con COVID-19.

Objective:To determine the predictive factors of pulmonary thromboembolic (PTE) in patients with SARS-CoV-2 infection (COVID-19) assessed in the emergency department at a tertiary hospital during the first pandemic wave.Methods:Observational single-center study conducted in a retrospective cohort of patients with confirmed SARS-CoV-2 infection (or high clinical-radiological suspicion) who underwent PTE screening by computed tomography pulmonary angiography (CTPA). Predictive factors of PTE were explored using logistic regression, creating two predictive models (without or with D-dimer values).Results:Out of a total of 274 CTPA performed, 70 procedures presented diagnostic findings of PTE, representing a cumulative incidence of 25.54% (95% confidence interval [CI]: 20.49-31.14). In the non–D-dimer based model, respiratory rate>22bpm (odds ratio [OR]: 3.162; 95% CI: 1.627-6.148; p=0.001) and the absence of findings suggestive of COVID-19 in plain chest X-ray (OR: 3.869; 95% CI: 0.869-17.225; p=0.076) were predictors of PTE. In the D-dimer-based model, tachypnea remained as a predictive factor (OR: 4.967; 95% CI: 2.053-12.018; p<0.001), as well as D-dimers>3,000ng/ml (OR: 7.494; 95% CI: 3.038-18.485; p<0.001).Conclusions:The presence of tachypnea (>22bpm) and the absence of radiological findings suggestive of SARS-CoV-2 infection in the chest X-ray, in addition to D-dimer values>3,000 ng/mL, were identified as predictive factors of PTE in patients with COVID-19. (AU)

Prediction of pulmonary embolism in patients with SARS-CoV-2 infection.

OBJECTIVE: To determine the predictive factors of pulmonary thromboembolic (PTE) in patients with SARS-CoV-2 infection (COVID-19) assessed in the emergency department at a tertiary hospital during the first pandemic wave. METHODS: Observational single-center study conducted in a retrospective cohort of patients with confirmed SARS-CoV-2 infection (or high clinical-radiological suspicion) who underwent PTE screening by computed tomography pulmonary angiography (CTPA). Predictive factors of PTE were explored using logistic regression, creating two predictive models (without or with D-dimer values). RESULTS: Out of a total of 274 CTPA performed, 70 procedures presented diagnostic findings of PTE, representing a cumulative incidence of 25.54% (95% confidence interval [CI]: 20.49-31.14). In the non-D-dimer based model, respiratory rate >22 bpm (odds ratio [OR]: 3.162; 95% CI: 1.627-6.148; p = 0.001) and the absence of findings suggestive of COVID-19 in plain chest X-ray (OR: 3.869; 95% CI: 0.869-17.225; p = 0.076) were predictors of PTE. In the D-dimer-based model, tachypnea remained as a predictive factor (OR: 4.967; 95% CI: 2.053-12.018; p < 0.001), as well as D-dimers > 3000 ng/mL (OR: 7.494; 95% CI: 3.038-18.485; p < 0.001). CONCLUSIONS: The presence of tachypnea (>22 bpm) and the absence of radiological findings suggestive of SARS-CoV-2 infection in the chest X-ray, in addition to D-dimer values >3000 ng/mL, were identified as predictive factors of PTE in patients with COVID-19.

OBJETIVO: Pretendemos determinar los factores predictores de enfermedad tromboembólica pulmonar (ETEP) en pacientes con infección por SARS-CoV-2 (COVID-19) atendidos en el servicio de urgencias de un hospital terciario durante la primera ola pandémica. MÉTODOS: Estudio observacional unicéntrico realizado en una cohorte retrospectiva de pacientes con infección confirmada por SARS-CoV-2 (o alta sospecha clínico-radiológica de COVID-19) sometidos a despistaje de ETEP mediante tomografía computarizada de arterias pulmonares (TCAP). Se exploraron los factores predictores de ETEP mediante regresión logística, creándose dos modelos predictivos (sin o con los valores de dímeros-D). RESULTADOS: De un total de 274 TCAP realizados, 70 procedimientos presentaron hallazgos diagnósticos de ETEP, representando una incidencia acumulada de 25,54% (intervalo de confianza [IC] 95%: 20,49­31,14). En el modelo no ajustado por el nivel de dímeros-D, la frecuencia respiratoria >22 rpm (odds ratio [OR]: 3,162; IC 95%: 1,627­6,148; p = 0,001) y la ausencia de hallazgos sugerentes de COVID-19 en la radiología simple de tórax (OR: 3,869; IC 95%: 0,869­17,225; p = 0,076) fueron predictores de ETEP. En el segundo modelo se mantuvo la presencia de taquipnea (OR: 4,967; IC 95%: 2,053­12,018; p < 0,001), identificándose además un nivel de dímeros-D > 3.000 ng/mL (OR: 7,494; IC 95%: 3,038­18,485; p < 0,001). CONCLUSIONES: La presencia de taquipnea (>22 rpm) y la ausencia de hallazgos radiológicos sugestivos de infección por SARS-CoV-2 en la radiografía simple de tórax, además de los valores de dímero-D > 3.000 ng/mL, fueron identificados como factores predictores de ETEP en pacientes con COVID-19.

[Prediction of pulmonary embolism in patients with SARS-CoV-2 infection]. / Predicción del desarrollo de tromboembolia pulmonar en pacientes con infección por SARS-CoV-2.

OBJECTIVE: To determine the predictive factors of pulmonary thromboembolic (PTE) in patients with SARS-CoV-2 infection (COVID-19) assessed in the emergency department at a tertiary hospital during the first pandemic wave. METHODS: Observational single-center study conducted in a retrospective cohort of patients with confirmed SARS-CoV-2 infection (or high clinical-radiological suspicion) who underwent PTE screening by computed tomography pulmonary angiography (CTPA). Predictive factors of PTE were explored using logistic regression, creating two predictive models (without or with D-dimer values). RESULTS: Out of a total of 274 CTPA performed, 70 procedures presented diagnostic findings of PTE, representing a cumulative incidence of 25.54% (95% confidence interval [CI]: 20.49-31.14). In the non-D-dimer based model, respiratory rate>22bpm (odds ratio [OR]: 3.162; 95% CI: 1.627-6.148; p=0.001) and the absence of findings suggestive of COVID-19 in plain chest X-ray (OR: 3.869; 95% CI: 0.869-17.225; p=0.076) were predictors of PTE. In the D-dimer-based model, tachypnea remained as a predictive factor (OR: 4.967; 95% CI: 2.053-12.018; p<0.001), as well as D-dimers>3,000ng/ml (OR: 7.494; 95% CI: 3.038-18.485; p<0.001). CONCLUSIONS: The presence of tachypnea (>22bpm) and the absence of radiological findings suggestive of SARS-CoV-2 infection in the chest X-ray, in addition to D-dimer values>3,000 ng/mL, were identified as predictive factors of PTE in patients with COVID-19.

Influence of the Gap between Substrates in the Laser-Induced Transference of High-Viscosity Pastes.

Laser-induced forward transfer for high-viscosity-of Pa·s-pastes differ from standard LIFT processes in its dynamics. In most techniques, the transference after setting a great gap does not modify the shape acquired by the fluid, so it stretches until it breaks into droplets. In contrast, there is no transferred material when the gap is bigger than three times the paste thickness in LIFT for high-viscosity pastes, and only a spray is observed on the acceptor using this configuration. In this work, the dynamics of the paste have been studied using a finite-element model in COMSOL Multiphysics, and the behavior of the paste varying the gap between the donor and the acceptor substrates has also been modeled. The paste bursts for great gaps, but it is confined when the acceptor is placed close enough. The obtained simulations have been compared with a previous work, in which the paste structures were photographed. The analysis of the simulations in terms of speed allows for predicting the burst of the paste-spray regime-and the construction of a printability map regarding the gap between the substrates.