Insights into NdIII to YbIII Energy Transfer and Its Implications in Luminescence Thermometry.

This work challenges the conventional approach of using NdIII 4F3/2 lifetime changes for evaluating the experimental NdIII → YbIII energy transfer rate and efficiency. Using near-infrared (NIR) emitting Nd:Yb mixed-metal coordination polymers (CPs), synthesized via solvent-free thermal grinding, we demonstrate that the NdIII [2H11/2 → 4I15/2] → YbIII [2F7/2 → 2F5/2] pathway, previously overlooked, dominates energy transfer due to superior energy resonance and J-level selection rule compatibility. This finding upends the conventional focus on the NdIII [4F3/2 → 4I11/2] → YbIII [2F7/2 → 2F5/2] transition pathway. We characterized Nd0.890Yb0.110(BTC)(H2O)6 as a promising cryogenic NIR thermometry system and employed our novel energy transfer understanding to perform simulations, yielding theoretical thermometric parameters and sensitivities for diverse Nd:Yb ratios. Strikingly, experimental thermometric data closely matched the theoretical predictions, validating our revised model. This novel perspective on NdIII → YbIII energy transfer holds general applicability for the NdIII/YbIII pair, unveiling an important spectroscopic feature with broad implications for energy transfer-driven materials design.

Contribution of Microorganisms with the Clade II Nitrous Oxide Reductase to Suppression of Surface Emissions of Nitrous Oxide.

The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis of nitrous oxide flux from observation wells and the proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape from the surface. To better understand the environmental controls of production and emission at this site, we used a combination of isotopic, geochemical, and molecular analyses to show that chemodenitrification and bacterial denitrification are major sources of nitrous oxide in this subsurface, where low DO, low pH, and high nitrate are correlated with significant nitrous oxide production. Depth-resolved metagenomes showed that consumption of nitrous oxide near the surface was correlated with an enrichment of Clade II nitrous oxide reducers, consistent with a growing appreciation of their importance in controlling release of nitrous oxide to the atmosphere. Our work also provides evidence for the reduction of nitrous oxide at a pH of 4, well below the generally accepted limit of pH 5.

Sex-based differences in growth-related IGF1 signaling in response to PAPP-A2 deficiency: comparative effects of rhGH, rhIGF1 and rhPAPP-A2 treatments.

BACKGROUND: Children with pregnancy-associated plasma protein-A2 (PAPP-A2) mutations resulting in low levels of bioactive insulin-like growth factor-1 (IGF1) and progressive postnatal growth retardation have improved growth velocity and height following recombinant human (rh)IGF1 treatment. The present study aimed to evaluate whether Pappa2 deficiency and pharmacological manipulation of GH/IGF1 system are associated with sex-specific differences in growth-related signaling pathways. METHODS: Plasma, hypothalamus, pituitary gland and liver of Pappa2ko/ko mice of both sexes, showing reduced skeletal growth, and liver of these mice treated with rhGH, rhIGF1 and rhPAPP-A2 from postnatal day (PND) 5 to PND35 were analyzed. RESULTS: Reduced body and femur length of Pappa2ko/ko mice was associated with increases in: (1) components of IGF1 ternary complexes (IGF1, IGFBP5/Igfbp5, Igfbp3, Igfals) in plasma, hypothalamus and/or liver; and (2) key signaling regulators (phosphorylated PI3K, AKT, mTOR, GSK3ß, ERK1/2 and AMPKα) in hypothalamus, pituitary gland and/or liver, with Pappa2ko/ko females having a more prominent effect. Compared to rhGH and rhIGF1, rhPAPP-A2 specifically induced: (1) increased body and femur length, and reduced plasma total IGF1 and IGFBP5 concentrations in Pappa2ko/ko females; and (2) increased Igf1 and Igf1r levels and decreased Ghr, Igfbp3 and Igfals levels in the liver of Pappa2ko/ko females. These changes were accompanied by lower phospho-STAT5, phospho-AKT and phospho-ERK2 levels and higher phospho-AMPK levels in the liver of Pappa2ko/ko females. CONCLUSIONS: Sex-specific differences in IGF1 system and signaling pathways are associated with Pappa2 deficiency, pointing to rhPAPP-A2 as a promising drug to alleviate postnatal growth retardation underlying low IGF1 bioavailability in a female-specific manner.

Understanding the physiological role of pregnancy-associated plasma protein-A2 (PAPP-A2), a proteinase involved in the insulin-like growth factor-1 (IGF1) availability to regulate growth, could provide insight into new treatments for patients with short stature and skeletal abnormalities. Although progressive postnatal growth retardation in patients with PAPP-A2 mutations can differ between males and females, we do not know the underlying differences in IGF1 system and signaling, and their response to treatment that contribute to growth improvement. The present study examines whether Pappa2 deficiency and pharmacological administration of rhGH, rhIGF1 and rhPAPP-A2 are associated with sex-specific differences in IGF1 ternary complexes and IGF1 signaling pathways. Reduced body and femur length of Pappa2-deficient mice was associated with sex- and tissue-specific alteration of IGF ternary/binary complexes and IGF1 signaling pathways. rhPAPP-A2 treatment induced female-specific increase in body and femur length and reduction in IGF ternary/binary complexes through STAT5-AKT-ERK2-AMPK signaling pathways in liver. The involvement of PAPP-A2 in sex-based growth physiology supports the use of promising drugs to alleviate postnatal growth retardation underlying low IGF1 bioavailability in a female-specific manner.

Morphology does not matter: WSe2 luminescence nanothermometry unravelled.

Transition metal dichalcogenides, including WSe2, have gained significant attention as promising nanomaterials for various applications due to their unique properties. In this study, we explore the temperature-dependent photoluminescent properties of WSe2 nanomaterials to investigate their potential as luminescent nanothermometers. We compare the performance of WSe2 quantum dots and nanorods synthesized using sonication synthesis and hot injection methods. Our results show a distinct temperature dependence of the photoluminescence, and conventional ratiometric luminescence thermometry demonstrates comparable relative thermal sensitivity (0.68-0.80% K-1) and temperature uncertainty (1.3-1.5 K), irrespective of the morphology of the nanomaterials. By applying multiple linear regression to WSe2 quantum dots, we achieve enhanced thermal sensitivity (30% K-1) and reduced temperature uncertainty (0.1 K), highlighting the potential of WSe2 as a versatile nanothermometer for microfluidics, nanofluidics, and biomedical assays.

Effect of a nutritional intervention based on an energy-reduced Mediterranean diet on environmental impact.

OBJECTIVE: To estimate the environmental impact of a dietary intervention based on an energy-reduced Mediterranean diet (MedDiet) after one year of follow-up. METHODS: Baseline and 1-year follow-up data were used for 5800 participants aged 55-75 years with metabolic syndrome in the PREDIMED-Plus study. Food intake was estimated through a validated semiquantitative food consumption frequency questionnaire, and adherence to the MedDiet was estimated through the Diet Score. Using the EAT-Lancet Commission tables we assessed the influence of dietary intake on environmental impact (through five indicators: greenhouse gas emissions (GHG), land use, energy used, acidification and potential eutrophication). Using multivariable linear regression models, the association between the intervention and changes in each of the environmental factors was assessed. Mediation analyses were carried out to estimate to what extent changes in each of 2 components of the intervention, namely adherence to the MedDiet and caloric reduction, were responsible for the observed reductions in environmental impact. RESULTS: We observed a significant reduction in the intervention group compared to the control group in acidification levels (-13.3 vs. -9.9 g SO2-eq), eutrophication (-5.4 vs. -4.0 g PO4-eq) and land use (-2.7 vs. -1.8 m2). Adherence to the MedDiet partially mediated the association between intervention and reduction of acidification by 15 %, eutrophication by 10 % and land use by 10 %. Caloric reduction partially mediated the association with the same factors by 55 %, 51 % and 38 % respectively. In addition, adherence to the MedDiet fully mediated the association between intervention and reduction in GHG emissions by 56 % and energy use by 53 %. CONCLUSIONS: A nutritional intervention based on consumption of an energy-reduced MedDiet for one year was associated with an improvement in different environmental quality parameters.

Discovery of selective monosaccharide receptors via dynamic combinatorial chemistry.

The molecular recognition of saccharides by synthetic hosts has become an appealing but elusive task in the last decades. Herein, we combine Dynamic Combinatorial Chemistry (DCC) for the rapid self-assembly and screening of virtual libraries of receptors, with the use of ITC and NMR to validate the hits and molecular modelling to understand the binding mechanisms. We discovered a minimalistic receptor, 1F (N-benzyl-L-phenylalanine), with considerable affinity for fructose (Ka = 1762 M-1) and remarkable selectivity (>50-fold) over other common monosaccharides. The approach accelerates the discovery process of receptors for saccharides.

Luminescent Ln3+-based silsesquioxanes with a ß-diketonate antenna ligand: toward the design of efficient temperature sensors.

We report the synthesis and single-crystal X-ray diffraction, magnetic, and luminescence measurements of a novel family of luminescent cage-like tetranuclear silsesquioxanes (PhSiO1.5)8(LnO1.5)4(O)(C5H8O2)6(EtOH)2(CH3CN)2⋅2CH3CN (where Ln = Tb, 1; Tb/Eu, 2; and Gd, 3), featuring seven-coordinated lanthanide ions arranged in a one-capped trigonal prism geometry. Compounds 1 and 2 exhibit characteristic Tb3+ and Tb3+/Eu3+-related emissions, respectively, sensitized by the chelating antenna acetylacetonate (acac) ligands upon excitation in the UV and visible spectral regions. Compound 3 is used to assess the energies of the triplet states of the acac ligand. For compound 1, theoretical calculations on the intramolecular energy transfer and multiphonon rates indicate a thermal balance between the 5D4 Stark components, while the mixed Tb3+/Eu3+ analog 2, with a Tb:Eu ratio of 3:1, showcases intra-cluster Tb3+-to-Eu3+ energy transfer, calculated theoretically as a function of temperature. By utilizing the intensity ratio between the 5D4→7F5 (Tb3+) and 5D0→7F2 (Eu3+) transitions in the range 11-373 K, we demonstrate the realization of a ratiometric luminescent thermometer with compound 2, operating in the range 11-373 K with a maximum relative sensitivity of 2.0% K-1 at 373 K. These findings highlight the potential of cage-like silsesquioxanes as versatile materials for optical sensing-enabled applications.

A trimeric glycosylated GH45 cellulase from the red abalone (Haliotis rufescens) exhibits endo and exoactivity.

The red abalone (Haliotis rufescens) represents North America's most important aquaculture species. Its hepatopancreas is rich in cellulases and other polysaccharide-degrading enzymes, which provide it the remarkable ability to digest cellulose-rich macroalgae; nevertheless, its cellulolytic systems are poorly explored. This manuscript describes some functional and structural properties of an endogenous trimeric glycosylated endoglucanase from H. rufescens. The purified enzyme showed a molecular mass of 23.4 kDa determined by MALDI-TOF mass spectrometry, which behaved as a homotrimer in gel filtration chromatography and zymograms. According to the periodic acid-Schiff reagent staining, detecting sugar moieties in SDS-PAGE gel confirmed that abalone cellulase is a glycoprotein. Hydrolysis of cello-oligosaccharides and p-nitrophenyl-ß-D-glucopyranosides confirmed its endo/exoactivity. A maximum enzyme activity toward 0.5% (w/v) carboxymethylcellulose of 53.9 ± 1.0 U/mg was achieved at 45°C and pH 6.0. We elucidated the abalone cellulase primary structure using proteases and mass spectrometry methods. Based on these results and using a bioinformatic approach, we identified the gene encoding this enzyme and deduced its full-length amino acid sequence; the mature protein comprised 177 residues with a calculated molecular mass of 19.1 kDa and, according to sequence similarity, it was classified into the glycosyl-hydrolase family 45 subfamily B. An AlphaFold theoretical model and docking simulations with cellopentaose confirmed that abalone cellulase is a ß-sheet rich protein, as also observed by circular dichroism experiments, with conserved catalytic residues: Asp26, Asn109, and Asp134. Interestingly, the AlphaFold-Multimer analysis indicated a trimeric assembly for abalone cellulase, which supported our experimental findings. The discovery and characterization of these enzymes may contribute to developing efficient cellulose bioconversion processes for biofuels and sustainable bioproducts.

Robotic surgery across Latin America: a bibliometric analysis of research trends from 2009 to 2022.

The rise of robotic surgery throughout the world, particularly in Latin America, justifies an objective evaluation of research in this field. This study aimed to use bibliometric techniques to identify the research trends and patterns of robotic surgery in Latin America. The research strategy used the terms "Robotic," "Surgery," and the name of all the Latin American countries, in all fields and collections of Web of Science database. Only original articles published between 2009 and 2022 were included. The software Rayyan, Bibliometric in the R Studio, and VOSViewer were used to develop the analyses. After screening, 96 articles were included from 60 different journals. There was a 22.51% annual increase in the scientific production of robotic surgery in the period studied. The more frequent topics by specialty were: Urology (35.4%), General Surgery (34.4%), and Obstetrics and Gynecology (12%). International cooperation was observed in 65.62% of the studies. The Latin American institution with the highest production of manuscripts was the Pontificia Universidad Católica de Chile. Mexico, Chile, and Brazil were, in descending order, the nations with the highest number of corresponding authors and total citations. When considering the total number of articles, Brazil ranked ahead of Chile. Scientific production regarding robotic surgery in Latin America has experienced accelerated growth since its beginning, supported by the high degree of collaboration with leading countries in the field.

Nutritional Deficiencies Before and After Bariatric Surgery in Low- and High-Income Countries: Prevention and Treatment.

Nutritional deficiencies represent a prevalent concern among individuals with obesity, stemming from suboptimal dietary habits, chronic inflammation, and preoperative weight reduction efforts. Bariatric surgical interventions, employing either restrictive, malabsorptive or a combination of the two methods, further compound these deficiencies. Commonly observed nutritional deficits following bariatric surgeries include vitamin B12, vitamin D, thiamine, folate, iron, and protein deficiencies. These deficiencies are further complicated by disparities in healthcare resources and income that distinguish low, medium, and high-income countries. The escalating rates of obesity in low- and medium-income countries are primarily attributed to the increasing availability of cheap, nutritionally depleted, and processed foods, coupled with limited access to healthcare. The provision of bariatric surgical interventions in such regions is hindered by the lack of appropriately trained medical personnel and adequate infrastructure. Additionally, the crucial facets of postoperative care, including diligent follow-up, precise weight loss monitoring, and the administration of appropriate nutritional supplements, often remain lacking. This narrative review provides a comprehensive examination of the prevention and treatment of nutritional deficiencies before and after bariatric surgery in the context of varying healthcare resources and income levels. Bariatric procedures and their global prevalence are discussed, and the prevalence, symptoms, and management strategies of specific nutritional deficiencies are explained. This review also outlines practical strategies for providing more equitable care in low- and medium-income countries.

Aquatic Exercise in Physical Therapy Treatment for Fibromyalgia: Systematic Review.

Fibromyalgia is a chronic condition characterized by musculoskeletal pain. The aim of this study was to synthesize scientific evidence on the effects of aquatic exercise programs on pain and quality of life in individuals with fibromyalgia. This review was carried out using the following databases in January 2024: Cochrane Library, PEDro, PubMed, SCOPUS, and Web of Science. Four clinical trials focusing on aquatic exercise as a treatment for patients with fibromyalgia were selected. These trials were published in English between 2019 and 2024. Pain recorded using the Visual Analog Scale (VAS) and quality of life with the Short Form-36 Health Survey (SF-36) or Fibromyalgia Impact on Quality of Life (FIQ) were the most commonly analyzed variables. This review was carried out according to the PRISMA statement and was registered in PROSPERO (CRD42024510219). The results in terms of pain and quality of life were positive. In conclusion, these findings support the incorporation of aquatic exercise into fibromyalgia physical therapy treatment. However, the benefits could be equivalent to those of other exercise modalities, underscoring the need for individualized adaptation to each patient's needs.

Downregulation of Serotonergic System Components in an Experimentally Induced Cryptorchidism in Rabbits.

Cryptorchidism (CO) or undescended testes is defined as the failure of one or both testes to be positioned inside the scrotum. Typically, cryptorchidism is detected at birth or shortly thereafter, and in humans, it is considered to be part of the testicular dysgenesis syndrome (TDS), a complex pathology regarding the male reproductive system that apparently involves the interaction of both genetic and environmental harmful factors, mainly during embryonic development. Serotonin (5-HT) is an ancient molecule that participates in a broad range of body functions, and in recent years, its importance in reproduction has started to be elucidated. In male pathologies such as infertility, varicocele, erectile dysfunction, and primary carcinoid tumors, an increase in 5-HT concentration or its metabolites in the blood, semen, and urine has been directly related; nevertheless, the role of 5-HT in CO remains unknown. In the present work, our goal was to answer two important questions: (1) whether some serotonergic system components are present in adult male Oryctolagus cuniculus (chinchilla rabbit) and (2) if there are changes in their expression in an experimental model of CO. Using histological, molecular, and biochemical approaches, we found the presence of some serotonergic system components in the adult chinchilla rabbit, and we demonstrated that its expression is downregulated after CO was pharmacologically induced. Although we did not test the role of 5-HT in the etiology of CO, our results suggest that this indoleamine could be important for the regulation of steroidogenesis and spermatogenesis processes in the chinchilla rabbit during adulthood. Finally, in parallel experimental series, we found downregulation of kynurenine concentration in COI rabbits when compared to control ones, suggesting that CO could be affecting the kynurenine pathway and probably testicular immune privilege which in turn could lead to infertility/sterility conditions in this disorder.

Pulsed negative pressure myofascial vacuum therapy and percutaneous electrolysis in the treatment of lateral epicondylalgia: A single-blind randomized controlled trial.

BACKGROUND: Lateral Epicondylalgia (LE) represents one of the most common injuries of the upper limb. It is necessary to find effective treatments that reduce pain and increase functionality. PURPOSE: To determine the effects of an integrated intervention of Pulsed Negative Pressure Myofascial Vacuum Therapy (VT), Percutaneous Electrolysis (PE) and eccentric exercise (EE) in the treatment of LE compared versus Manual Therapy soft tissue mobilization (MT) and Ultrasound therapy (US) and EE. STUDY DESIGN: Single-blind randomized controlled trial. METHODS: Forty participants, with unilateral LE, were randomly divided into two groups: VT + PE + EE group (n = 20) and MT + US + EE group (n = 20). The VT + PE + EE group received one weekly session for four weeks and a regimen of EE daily at-home, and the MT + US + EE group received 10 sessions over a period of two weeks and a regimen of EE daily at-home. Numerical pain rating scale (NPRS), range of motion (ROM) pressure pain threshold (PPT) and function (PRTEE questionnaire) were measured before treatment, at the end of treatment, and at one- and three-month follow-ups. RESULTS: The statistically significant improvements were found post-treatment, favoring the VT + PE group in pain intensity (p < 0.001; ES = 0.408), PRTEE-S Pain (p = 0.001; ES = 0.377), PRTEE-S Specific function (p = 0.004; ES = 0.306) and PRTEE-S Total (p = 0.001; ES = 0.355). The VT + PE + EE treatment showed greater effectiveness than the MT + US + EE treatment at immediate post-treatment, as well as at the one-month and three-months follow-up. CONCLUSIONS: VT and PE added to an EE program could be an effective treatment for pain, ROM, PPT, and function in patients with LE.

New hard tick (Acari: Ixodidae) reports and detection of Rickettsia in ticks from Sierra Nevada de Santa Marta, Colombia.

The Sierra Nevada de Santa Marta (SNSM), located in northern Colombia, is considered a geographical island with high levels of biodiversity and endemism. However, little is known about tick species and their associated microorganisms at the SNSM. In this study we sampled host-seeking ticks in areas of the town of Minca within the SNSM. We collected 47 ticks identified as Amblyomma pacae, Amblyomma longirostre, Amblyomma ovale, Amblyomma mixtum, Haemaphysalis juxtakochi, Ixodes sp. cf. Ixodes affinis and Ixodes sp. Of these ticks, we tested for Rickettsia spp. by amplifying the gltA, SCA1, and 16S rRNA genes via PCR. Rickettsia amblyommatis was detected in one pool of 3 larvae and in a female of A. pacae. Additonally, we isolated Rickettsia sp. belonging to the group of spotted fevers in larvae of A. longirostre. This study reports new findings of six species of ticks and two species of Rickettsia within the SNSM.

Double myelomeningocele repair by fetal surgery with a single micro-hysterotomy.

INTRODUCTION: Open spina bifida (OSB) is the most common congenital anomaly of the central nervous system. It is associated with severe neurodevelopmental delay, motor impairment, hydrocephalus, and bowel and bladder dysfunction. In selected cases, intrauterine spina bifida repair has been shown to improve neonatal outcomes. Rarely, the spine can have a double defect compromising two different segments and there is a lack of evidence on the feasibility and benefits of intrauterine repair in these cases. CASE PRESENTATION: We present a case with both cervicothoracic and lumbosacral myelomeningocele, Arnold-Chiari malformation type II, and bilateral ventriculomegaly, that was treated successfully at 25 weeks with open micro-neurosurgery. Double myelomeningocele was successfully treated through a single 2cm micro-hysterotomy, by performing external versions to sequentially expose and repair both defects. Weekly postoperative follow-up showed no progression of ventriculomegaly or complications attributable to the procedure. Preterm rupture of membranes prompted a conventional cesarean delivery at 32 weeks of gestation. Neurodevelopmental outcome at 20 months was within normal ranges, having achieved ambulation without orthopedic support, and with no need for ventriculoperitoneal shunting. CONCLUSION: This report demonstrates for the first time the feasibility of double OSB repair through a single 2cm micro-hysterotomy, suggesting that selected isolated cases of double myelomeningocele could be candidates for fetal intervention. Further prospective studies should be carried out to assess the potential benefit of double OSB intrauterine open repair.

Exploring the Luminescence, Redox, and Magnetic Properties in a Multivariate Metal-Organic Radical Framework.

Persistent neutral organic radicals are excellent building blocks for the design of functional molecular materials due to their unique electronic, magnetic, and optical properties. Among them, triphenylmethyl radical derivatives have attracted a lot of interest as luminescent doublet emitters. Although neutral organic radicals have been underexplored as linkers for building metal-organic frameworks (MOFs), they hold great potential as organic elements that could introduce additional electronic properties within these frameworks. Herein, we report the synthesis and characterization of a novel multicomponent metal-organic radical framework (PTMTCR@NR-Zn MORF), which is constructed from the combination of luminescent perchlorotriphenylmethyl tricarboxylic acid radical (PTMTCR) and nonemissive nonradical (PTMTCNR) organic linkers and Zn(II) ions. The PTMTCR@NR-Zn MORF structure is layered with microporous one-dimensional channels embedded within these layers. Kelvin probe force microscopy further confirmed the presence of both organic nonradical and radical linkers in the framework. The luminescence properties of the PTMTCR ligand (first studied in solution and in the solid state) were maintained in the radical-containing PTMTCR@NR-Zn MORF at room temperature as fluorescence solid-state quenching is suppressed thanks to the isolation of the luminescent radical linkers. In addition, magnetic and electrochemical properties were introduced to the framework due to the incorporation of the paramagnetic organic radical ligands. This work paves the way for the design of stimuli-responsive hybrid materials with tunable luminescence, electrochemical, and magnetic properties by the proper combination of closed- and open-shell organic linkers within the same framework.

Autonomous Robotic Surgery: Has the Future Arrived?

Autonomous robotic surgery represents a pioneering field dedicated to the integration of robotic systems with varying degrees of autonomy for the execution of surgical procedures. This paradigm shift is made possible by the progressive integration of artificial intelligence (AI) and machine learning (ML) into the realm of surgical interventions. While the majority of autonomous robotic systems remain in the experimental phase, a notable subset has successfully transitioned into clinical applications. Noteworthy procedures, such as venipuncture, hair implantations, intestinal anastomosis, total knee replacement, cochlear implant, radiosurgery, and knot tying, among others, exemplify the current capabilities of autonomous surgical systems. This review endeavors to comprehensively address facets of autonomous robotic surgery, commencing with a concise elucidation of fundamental concepts and traversing the pivotal milestones in the historical evolution of robotic surgery. This historical trajectory underscores the incremental assimilation of autonomous systems into surgical practices. This review aims to address topics related to autonomous robotic surgery, starting with a description of fundamental concepts and going through the milestones in robotic surgery history that also show the gradual incorporations of autonomous systems. It also includes a discussion of the key benefits and risks of this technology, the degrees of autonomy in surgical robots, their limitations, the current legal regulations governing their usage, and the main ethical concerns inherent to their nature.

Monte Carlo simulation of the Varian TrueBeam flattened-filtered beams using a surrogate geometry in PRIMO.

BACKGROUND: Monte Carlo simulation of radiation transport for medical linear accelerators (linacs) requires accurate knowledge of the geometrical description of the linac head. Since the geometry of Varian TrueBeam machines has not been disclosed, the manufacturer distributes phase-space files of the linac patient-independent part to allow researchers to compute absorbed dose distributions using the Monte Carlo method. This approach limits the possibility of achieving an arbitrarily small statistical uncertainty. This work investigates the use of the geometry of the Varian Clinac 2100, which is included in the Monte Carlo system PRIMO, as a surrogate. METHODS: Energy, radial and angular distributions extracted from the TrueBeam phase space files published by the manufacturer and from phase spaces tallied with PRIMO for the Clinac 2100 were compared for the 6, 8, 10 and 15 MV flattened-filtered beams. Dose distributions in water computed for the two sets of PSFs were compared with the Varian Representative Beam Data (RBD) for square fields with sides ranging from 3 to 30 cm. Output factors were calculated for square fields with sides ranging from 2 to 40 cm. RESULTS: Excellent agreement with the RBD was obtained for the simulations that employed the phase spaces distributed by Varian as well as for those that used the surrogate geometry, reaching in both cases Gamma ([Formula: see text], 2 mm) pass rates larger than [Formula: see text], except for the 15 MV surrogate. This result supports previous investigations that suggest a change in the material composition of the TrueBeam 15 MV flattening filter. In order to get the said agreement, PRIMO simulations were run using enlarged transport parameters to compensate the discrepancies between the actual and surrogate geometries. CONCLUSIONS: This work sustains the claim that the simulation of the 6, 8 and 10 MV flattening-filtered beams of the TrueBeam linac can be performed using the Clinac 2100 model of PRIMO without significant loss of accuracy.

Expert-based collaborative analysis of the situation and prospects of biomarker test implementation in oncology in Spain.

PURPOSE: Biomarkers as screening for precision medicine is a fundamental step. The purpose of this article is twofold. First, to highlight the existing barriers in the implementation of Precision Medicine in Spain, with a special emphasis on barriers in access to the determination of biomarkers. Second, to provide a Roadmap that can help implement Precision Medicine equitably at the national level and optimize the use of biomarkers. METHODS: A systematic review of literature (SRL) and a focus group (FG) with multidisciplinary experts has been carried out in 2023. Participants were contacted individually, and discourse analysis was processed anonymously. RESULTS: We carried out a quantitative (SRL) and a qualitative approach (FG). The discourse analysis and roadmap were sent individually to each expert for approval. CONCLUSIONS: The potential of Precision Medicine has not been fulfilled in Spain. While several regional initiatives are in place, a national plan or strategy around Precision Medicine and use of biomarkers is lacking. In a general context of rapid progress at a global and European level, including the 2021 Europe's Beating Cancer Plan, it is time to define and implement a National Plan to make the promise come true. While some comparable countries within Europe - such as the UK or France - are mature enough to adopt such strategies, in Spain there is still a long way to go. We consider that the different strands of work outlined in the Roadmap can be used as basis for such purpose.