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3.
HardwareX ; 18: e00524, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38633332

RESUMO

Marine organisms are often subject to numerous anthropogenic stressors, resulting in widespread ecosystem degradation. Physiological responses to these stressors, however, are complicated by high biological variability, species-specific sensitivities, nonlinear relationships, and countless permutations of stressor combinations. Nevertheless, quantification of these relationships is paramount for parameterizing predictive tools and ultimately for effective management of marine resources. Multi-level, multi-stressor experimentation is therefore key, yet the high replication required has remained a logistical challenge and a financial barrier. To overcome these issues, we created an automated system for experimentation on marine organisms, the Sequential Treatment Application Robot (STAR). The system consists of a track-mounted robotic arm that sequentially applies precision treatments to independent aquaria via syringe and peristaltic pumps. The accuracy and precision were validated with dye and spectrophotometry, and stability was demonstrated by maintaining corals under treatment conditions for more than a month. The system is open source and scalable in that additional treatments and replicates may be added without incurring multiplicative costs. While STAR was designed for investigating the combined impacts of nutrients, warming, and disease on reef-building corals, it is highly customizable and may be used for experimentation involving a diverse array of treatments and species.

4.
Cell Death Dis ; 15(3): 223, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38493149

RESUMO

Spalt-like proteins are Zinc finger transcription factors from Caenorhabditis elegans to vertebrates, with critical roles in development. In vertebrates, four paralogues have been identified (SALL1-4), and SALL2 is the family's most dissimilar member. SALL2 is required during brain and eye development. It is downregulated in cancer and acts as a tumor suppressor, promoting cell cycle arrest and cell death. Despite its critical functions, information about SALL2 regulation is scarce. Public data indicate that SALL2 is ubiquitinated and phosphorylated in several residues along the protein, but the mechanisms, biological consequences, and enzymes responsible for these modifications remain unknown. Bioinformatic analyses identified several putative phosphorylation sites for Casein Kinase II (CK2) located within a highly conserved C-terminal PEST degradation motif of SALL2. CK2 is a serine/threonine kinase that promotes cell proliferation and survival and is often hyperactivated in cancer. We demonstrated that CK2 phosphorylates SALL2 residues S763, T778, S802, and S806 and promotes SALL2 degradation by the proteasome. Accordingly, pharmacological inhibition of CK2 with Silmitasertib (CX-4945) restored endogenous SALL2 protein levels in SALL2-deficient breast MDA-MB-231, lung H1299, and colon SW480 cancer cells. Silmitasertib induced a methuosis-like phenotype and cell death in SW480 cells. However, the phenotype was significantly attenuated in CRISPr/Cas9-mediated SALL2 knockout SW480 cells. Similarly, Sall2-deficient tumor organoids were more resistant to Silmitasertib-induced cell death, confirming that SALL2 sensitizes cancer cells to CK2 inhibition. We identified a novel CK2-dependent mechanism for SALL2 regulation and provided new insights into the interplay between these two proteins and their role in cell survival and proliferation.


Assuntos
Caseína Quinase II , Neoplasias do Colo , Animais , Humanos , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neoplasias do Colo/genética , Linhagem Celular Tumoral
5.
Rev. esp. anestesiol. reanim ; 71(3): 160-170, Mar. 2024. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-230929

RESUMO

Introducción: La artroplastia total de cadera es una de las intervenciones quirúrgicas más frecuentes en el contexto hospitalario. Sin embargo, sigue desconociéndose el método ideal para manejar el dolor postoperatorio. Las técnicas de analgesia multimodal basadas en la anestesia regional se encuentran entre las soluciones más prometedoras. Objetivos: El objetivo de este estudio fue evaluar el dolor postoperatorio tras la artroplastia total de cadera, de acuerdo con si se realizaron, o no, bloqueos del nervio periférico (bloqueo femoral, bloqueo de la fascia iliaca y bloqueo del grupo de nervios pericapsulares). Se midió el consumo de morfina intravenosa durante la estancia del paciente en la unidad de cuidados posanestésicos, así como el número de rescates con opioides transcurridas 24 y 48 h de la intervención. Como objetivos secundarios, se establecieron la prevalencia de la lesión nerviosa, la prolongación del bloqueo cuadricipital y el consumo de morfina, de acuerdo con otras variables de interés. Materiales y métodos: En este estudio retrospectivo observacional, se recopilaron datos de la historia clínica digital de 656 pacientes de cirugía traumatológica de abril de 2018 a agosto de 2020, con los criterios de inclusión siguientes: mayores de 18 años, ASA I-III, artroplastia total de cadera primaria con anestesia general o anestesia subaracnoidea (solo con bupivacaína hiperbárica) y uso de levobupivacaína para el bloqueo del nervio periférico. Resultados: Se seleccionó un total de 362 pacientes. La indicación quirúrgica principal fue coxartrosis (61,3%), seguida de fractura de cadera (22,6%). Se realizaron bloqueos del nervio periférico en 169 pacientes (66,3% femoral, 27,7% PENG, y 6% de fascia ilíaca). El consumo medio postoperatorio de opioides en la UCPA fue inferior en los pacientes que recibieron bloqueo PENG (2,2 mg) o femoral (3,27 mg), en comparación con los que no recibieron ninguno de los dos (6,69 mg)...(AU)


Introduction: Total hip arthroplasty is one of the most frequent surgical interventions in the hospital setting. Nonetheless, the ideal method to manage post-operative pain is still unknown. Multimodal analgesia techniques based on regional anaesthesia are amongst the most promising solutions. Objectives: The aim of this study was to evaluate postoperative pain after total hip arthroplasty according to whether peripheral nerve block was performed (femoral block, fascia iliaca block and pericapsular nerve group block). Intravenous morphine consumption during the patient's stay in the post-anaesthesia care unit was measured, as well as the number of opioid rescues at 24 and 48h post intervention. As secondary objectives, the prevalence of nerve injury, prolonged quadricipital block, and morphine consumption were established according to other variables of interest. Materials and methods: In this observational retrospective study, data was collected from the electronic medical record of 656 traumatological surgery patients from April 2018 to August 2020, with the following inclusion criteria: over 18 years old, ASA I-III, primary total hip arthroplasty under general anaesthesia or subarachnoid anaesthesia (only with hyperbaric bupivacaine) and use of levobupivacaine for peripheral nerve block. Results: A total of 362 patients were selected. The main surgical indication was coxarthrosis (61.3%), followed by hip fracture (22.6%). Peripheral nerve blocks were performed on 169 patients (66.3% femoral, 27.7% PENG, and 6.0% fascia iliaca). Mean postoperative opioid consumption in PACU was lower in patients in who received a PENG (2.2 mg) or a femoral (3.27 mg) block, compared to those who received neither (6.69 mg). There were no differences in opioid rescues at 24 and 48h after the procedure...(AU)


Assuntos
Humanos , Masculino , Feminino , Lesões do Quadril/cirurgia , Fraturas do Quadril/cirurgia , Artroplastia de Quadril , Anestesia por Condução , Estudos Retrospectivos , Anestesiologia , Quadril/cirurgia , Analgesia
8.
Nanotechnology ; 35(26)2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38527360

RESUMO

(In, Ga) alloy droplets are used to catalyse the growth of (In, Ga)As nanowires by molecular beam epitaxy on Si(111) substrates. The composition, morphology and optical properties of these nanowires can be tuned by the employed elemental fluxes. To incorporate more than 10% of In, a high In/(In+Ga) flux ratio above 0.7 is required. We report a maximum In content of almost 30% in bulk (In, Ga)As nanowires for an In/(In+Ga) flux ratio of 0.8. However, with increasing In/(In+Ga) flux ratio, the nanowire length and diameter are notably reduced. Using photoluminescence and cathodoluminescence spectroscopy on nanowires covered by a passivating (In, Al)As shell, two luminescence bands are observed. A significant segment of the nanowires shows homogeneous emission, with a wavelength corresponding to the In content in this segment, while the consumption of the catalyst droplet leads to a spectrally-shifted emission band at the top of the nanowires. The (In,Ga)As nanowires studied in this work provide a new approach for the integration of infrared emitters on Si platforms.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38354775

RESUMO

INTRODUCTION: Total hip arthroplasty is one of the most frequent surgical interventions in the hospital setting. Nonetheless, the ideal method to manage post-operative pain is still unknown. Multimodal analgesia techniques based on regional anaesthesia are amongst the most promising solutions. OBJECTIVES: The aim of this study was to evaluate postoperative pain after total hip arthroplasty according to whether peripheral nerve block was performed (femoral block, fascia iliaca block and pericapsular nerve group block). Intravenous morphine consumption during the patient's stay in the post-anaesthesia care unit was measured, as well as the number of opioid rescues at 24 and 48 h post intervention. As secondary objectives, the prevalence of nerve injury, prolonged quadricipital block, and morphine consumption were established according to other variables of interest. MATERIALS AND METHODS: In this observational retrospective study, data was collected from the electronic medical record of 656 traumatological surgery patients from April 2018 to August 2020, with the following inclusion criteria: over 18 years old, ASA I-III, primary total hip arthroplasty under general anaesthesia or subarachnoid anaesthesia (only with hyperbaric bupivacaine) and use of levobupivacaine for peripheral nerve block. RESULTS: A total of 362 patients were selected. The main surgical indication was coxarthrosis (61.3%), followed by hip fracture (22.6%). Peripheral nerve blocks were performed on 169 patients (66.3% femoral, 27.7% PENG, and 6.0% fascia iliaca). Mean postoperative opioid consumption in PACU was lower in patients in who received a PENG (2.2 mg) or a femoral (3.27 mg) block, compared to those who received neither (6.69 mg). There were no differences in opioid rescues at 24 and 48 h after the procedure. Nerve injury incidence was low (.8%), and not associated with nerve blocks. The incidence of prolonged quadricipital paralysis was also low (1.3%), and was mainly associated with femoral nerve block (75% of cases). CONCLUSIONS: This retrospective study supports the use of regional blocks as opioid-sparing techniques, highlighting their role in rapid functional recovery with no motor impairment.

10.
Climacteric ; : 1-6, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38308574

RESUMO

OBJECTIVE: There are limited studies on urogenital symptoms in women who experience menopause before the age of 40 years due to primary ovarian insufficiency (POI) or bilateral oophorectomy (surgical POI). This study aimed to compare the urogenital symptoms, including sexuality, of women with POI to those without the condition. METHODS: This cross-sectional study conducted was in seven Latin American countries, in which postmenopausal women (with POI and non-POI) were surveyed with a general questionnaire, the Menopause Rating Scale (MRS) and the six-item Female Sexual Function Index (FSFI-6). The association of premature menopause with more urogenital symptoms and lower sexual function was evaluated with logistic regression analysis. RESULTS: Women with POI experience more urogenital symptoms (MRS urogenital score: 3.54 ± 3.16 vs. 3.15 ± 2.89, p < 0.05) and have lower sexual function (total FSFI-6 score: 13.71 ± 7.55 vs. 14.77 ± 7.57 p < 0.05) than women who experience menopause at a normal age range. There were no significant differences in symptoms when comparing women based on the type of POI (idiopathic or surgical). After adjusting for covariates, our logistic regression model determined that POI is associated with more urogenital symptoms (odds ratio [OR]: 1.38, 95% confidence interval [CI] 1.06-1.80) and lower sexual function (OR: 1.67, 95% CI 1.25-2.25). CONCLUSION: POI, whether idiopathic or secondary to bilateral oophorectomy, is associated with symptoms that affect vaginal and sexual health.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38395302

RESUMO

INTRODUCTION: During the SARS-CoV-2 pandemic, several corticosteroid regimens have been used in the treatment of the disease, with disparate results according to drug and regimen used. For this reason, we wanted to analyze differences in early mortality derived from the use of different regimens of dexamethasone and methylprednisolone in SARS-CoV-2 infection in critically ill patients requiring admission to an ICU. METHOD: Observational, analytical and retrospective study, in an intensive care unit of a third-level university hospital, (March 2020 and June 2021). Adult patients (>18 years old) who were admitted consecutively for proven SARS-CoV-2 infection were included. The association with mortality in ICU at 28 days, different corticosteroid regimens used, was analyzed using a Cox proportional risk regression model. RESULTS: Data from a cohort of 539 patients were studied. Patient age (RR: 1.06; 95% CI: 1.02-1.10; P=<0.01) showed a significant association with 28-day mortality in the ICU. In the comparison of the different corticosteroid regimens analyzed, taking as a reference those patients who did not receive corticosteroid treatment, the dose of dexamethasone of 6mg/day showed a clear trend towards statistical significance as a protector of mortality at 28 days in the ICU (RR: 0.40, 95% CI: 0.15-1.02, p=0.05). The dose of dexamethasone of 6mg/day and low doses of methylprednisolone show a similar association with survival at 28 days (OR: 1.19; 95% CI: 0.63-2.26). CONCLUSIONS: The use of corticosteroids has been associated with better mortality outcomes in severe cases of SARS-CoV-2 infection. However, the therapeutic benefits of corticosteroids are not limited to dexamethasone alone.

12.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38253236

RESUMO

INTRODUCTION: Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favourable results. MATERIALS AND METHODS: Sixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35-68 years), with a mean follow-up of 7 years (range 1-15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term. RESULTS: All the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28-79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilising in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision. CONCLUSION: This procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

13.
J Ultrasound ; 27(1): 61-65, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37450197

RESUMO

BACKROUND: Dermatofibrosarcoma protuberans (DFSP) is a low-grade spindle cell sarcoma of fibroblastic origin. This tumor originates in the dermis and infiltrates the subcutaneous tissue. The highest incidence occurs in the third and fourth decades of life, affecting most frequently the trunk and proximal extremities. Ultrasound is performed in those cases where the clinical appearance of the lesion is not typical and when the physician wants to determine the extent and depth of the lesion. MATERIAL AND METHODS: Retrospective analysis of the ultrasound and demographic findings of thirteen patients with DFSP. RESULTS: 13 patients, 8 females and 5 males, aged from 2 months to 58 years old. One patient with two different separated synchronous tumors. On ultrasonography they compromised the dermal hypodermal layers in 93% of the cases and 1 dermal lesion. The compromise reached the aponeurotic plane in two cases. The sized varied from 5 to 38 mm. They presented as a well-defined hypoechogenic nodule in seven cases (50%). In three cases (21%) they presented as a hypoechogenic infiltrate ill-defined border solid lesion; in two cases as a plaque ill-defined lesion, and two cases as a pseudonodular inflammatory lesion with irregular borders. All lesions appeared vascularized on color Doppler imaging. CONCLUSION: DFSP is a low grade sarcoma of fibroblastic origin, that usually arises in the dermis and infiltrates the subcutaneous tissue. The clinical presentations are variable. On ultrasound we found different patterns: well-defined hypoechogenic solid nodule, hypoechogenic infiltrate ill-defined border solid lesion, plaque ill-defined lesion, and pseudonodular inflammatory lesion. It is important to know and recognize this suspicious different ultrasound presentations in order to recommend a histological study.


Assuntos
Dermatofibrossarcoma , Neoplasias Cutâneas , Feminino , Masculino , Humanos , Dermatofibrossarcoma/diagnóstico por imagem , Estudos Retrospectivos , Gordura Subcutânea , Ultrassonografia , Neoplasias Cutâneas/diagnóstico por imagem
15.
Oper Dent ; 49(1): 20-33, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38057996

RESUMO

PURPOSE: The objective of this double-blind, split-mouth, randomized clinical trial was to evaluate the color match of a single-shade composite resin Admira Fusion X-tra in comparison with a multi-shade composite resin Admira Fusion in non-carious cervical lesion restorations (NCCLs). METHODS AND MATERIALS: One hundred and twenty restorations were performed on NCCLs with two restorative materials (n=60). After prophylaxis, the teeth were isolated with a rubber dam, and one universal adhesive was applied in the selective enamel etching strategy. For both groups, the restorations were inserted incrementally and light-cured. The values of the coordinates L*, a*, and b* in the cervical third before vs after the restorations and cervical vs middle third after the restorations were evaluated using a digital spectrophotometer after the coordinate values were used to calculate the CIEDE (ΔE00). The restorations were evaluated at baseline and after 7 days of clinical performance according to the FDI criteria. Statistical analysis was performed using the Chi-square test for all parameters. Color change was analyzed by Student t-test for paired samples (α=0.05). RESULTS: All restorations were evaluated after 7 days. Regarding the color measurement, no significant difference was observed when Admira Fusion was compared to Admira Fusion X-tra for any of the comparisons performed (p>0.05). However, the values of ΔE00 in the cervical third before vs after the restorations were higher when compared with ΔE00 observed when the cervical vs middle third after restorations were compared. All restorations received the score "clinically very good" after 7 days for all outcomes, including the subjective color match, when evaluated for FDI criterion. CONCLUSIONS: The single-shade composite resin used achieves the same color match when compared to a multi-shade composite resin after 7 days in NCCLs.


Assuntos
Resinas Compostas , Restauração Dentária Permanente , Resinas Compostas/uso terapêutico , Restauração Dentária Permanente/métodos , Seguimentos , Materiais Dentários , Cimentos de Resina , Cor , Adaptação Marginal Dentária
16.
Ann Oncol ; 35(3): 293-301, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38092228

RESUMO

BACKGROUND: Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results. PATIENTS AND METHODS: Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician. RESULTS: From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%. CONCLUSIONS: In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.


Assuntos
Anticorpos Monoclonais Humanizados , Camptotecina/análogos & derivados , Imunoconjugados , Neoplasias de Mama Triplo Negativas , Humanos , Pessoa de Meia-Idade , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Terapia Neoadjuvante , Antígeno Ki-67 , Antígenos de Neoplasias/genética , Imunoconjugados/efeitos adversos
17.
Life Sci Space Res (Amst) ; 39: 67-75, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37945091

RESUMO

We report the results of the first six years of measurements of the energetic particle radiation environment on the International Space Station (ISS) with the Radiation Assessment Detector (ISS-RAD), spanning the period from February 2016 to February 2022. The first RAD was designed and built for MSL, the Mars Science Laboratory rover, also known as Curiosity; it has been operating on Mars since 2012 and is referred to here as MSL-RAD. ISS-RAD combines two sensor heads, one nearly identical to the single MSL-RAD sensor head, the other with greatly enhanced sensitivity to fast neutrons. These two sensor heads are referred to as the Charged Particle Detector (CPD) and Fast Neutron Detector (FND), respectively. Despite its name, the CPD is also capable of measuring high-energy neutrons and γ-rays, as is MSL-RAD. ISS-RAD was flown to the ISS in December 2015 and was deployed in February 2016, initially in the USLab module. RAD was used as a survey instrument from January 2017 through May 2020, when the instrument was positioned in the USLab and set to a zenith-pointing orientation. The energetic particle environment on the ISS is complex and varies on short time scales owing to the orbit, which has a 51.6∘ inclination with respect to the equator and has had an altitude in the 400-440 km range in this time period. The ISS moves continuously through the geomagnetic field, the strength of which varies with latitude, longitude, and altitude. The orbit passes through the South Atlantic Anomaly (SAA) several times a day, where magnetically trapped protons and electrons produce large but transient increases in observed fluxes and absorbed dose rates. The environment inside the ISS is affected by the solar cycle, altitude, and the local shielding, which varies between different ISS modules. We report results for charged particle absorbed dose and dose equivalent rates in various positions in the ISS. In an accompanying paper, we report similar results for neutron dose equivalent rates obtained with the ISS-RAD Fast Neutron Detector.


Assuntos
Radiação Cósmica , Monitoramento de Radiação , Proteção Radiológica , Monitoramento de Radiação/métodos , Nêutrons , Prótons
18.
Life Sci Space Res (Amst) ; 39: 76-85, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37945092

RESUMO

We report the results of the first six years of measurements of so-called fast neutrons on the International Space Station (ISS) with the Radiation Assessment Detector (ISS-RAD), spanning the period from February 2016 to February 2022. ISS-RAD combines two sensor heads, one nearly identical to the single sensor head in the Mars Science Laboratory RAD (MSL-RAD). The latter is described in a companion article to this one. The novel sensor is the FND, or fast neutron detector, designed to measure neutrons with energies in the range from 200 keV to about 8 MeV. ISS-RAD was deployed in February 2016 in the USLAB module, and then served as a survey instrument from March 2017 until May 2020. Data were acquired in Node3, the Japanese Pressurized Module, Columbus, and Node2. At the conclusion of the survey portion of RAD's planned 10-year campaign on ISS, the instrument was stationed in the USLAB; current plans call for it to remain there indefinitely. The radiation environment on the ISS consists of a complex mix of charged and neutral particles that varies on short time scales owing to the Station's orbit. Neutral particles, and neutrons in particular, are of concern from a radiation protection viewpoint, because they are both highly penetrating (since they do not lose energy via direct ionization) and, at some energies, have high biological effectiveness. Neutrons are copiously produced by GCRs and other incident energetic particles when they undergo nuclear interactions in shielding. As different ISS modules have varying amounts of shielding, they also have varying neutron environments. We report results for neutron fluences and dose equivalent rates in various positions in the ISS.


Assuntos
Radiação Cósmica , Monitoramento de Radiação , Voo Espacial , Astronave , Nêutrons Rápidos , Monitoramento de Radiação/métodos , Nêutrons , Doses de Radiação
19.
Life Sci Space Res (Amst) ; 39: 86-94, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37945093

RESUMO

The energetic particle radiation environment on the International Space Station (ISS) includes both charged and neutral particles. Here, we make use of the unique capabilities of the Radiation Assessment Detector (ISS-RAD) to measure both of these components simultaneously. The Charged Particle Detector (CPD) is, despite its name, capable of measuring neutrons in the energy range from about 4 MeV to a few hundred MeV. Combined with data from the Fast Neutron Detector (FND) in the 0.2 to 8 MeV range, we present the first broad-spectrum measurements of the neutron environments in various locations within the ISS since an early Bonner-Ball experiment that was conducted before the Station was fully constructed. The data presented here span the time period from February 2016 to February 2022. In addition to presenting broad-spectrum neutron fluence measurements, we show correlations of the measured neutron dose equivalent with charged-particle dose rates. The ratio of charged-particle dose to neutron dose equivalent is found to be relatively stable within the ISS.


Assuntos
Radiação Cósmica , Monitoramento de Radiação , Nêutrons Rápidos , Astronave , Doses de Radiação , Monitoramento de Radiação/métodos , Nêutrons
20.
Plant Biol (Stuttg) ; 25(7): 1091-1100, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37850399

RESUMO

The genus Psittacanthus (Loranthaceae) is widely distributed in the Neotropical region, where it is known for its large, colourful, scentless flowers. Until very recently, all Psittacanthus species were regarded as exclusively hummingbird-pollinated and the large species radiation in the genus attributed to the interactions with bird dispersers and pollinators. P. eucalyptifolius (Kunth) G.Don. is the only species reported as bee-pollinated. Here we describe the floral biology, floral visitors, and the reproductive system of P. eucalyptifolius in an Amazonian savanna, Brazil. We also compare the pollination success (reproductive performance) among different Psittacanthus species reported in previous studies. Psittacanthus eucalyptifolius produces sweet-scented flowers, and a small quantity of concentrated nectar. At least five species of scopate bees were recorded visiting and carrying pollen of P. eucalyptifolius. Xylocopa frontalis carried most pollen, visited more flowers, remained longer, and touched reproductive parts of flowers in >95% of the observed visits. Experiments indicate that P. eucalyptifolius is partially autocompatible (39% autonomous pollination) but depends on pollinators to achieve higher performance (~78% in control), indicating that bees can be as effective as birds in pollinating this group of mistletoes.


Assuntos
Loranthaceae , Erva-de-Passarinho , Viscum album , Animais , Abelhas , Aves , Flores , Néctar de Plantas , Polinização
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