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1.
Sci Rep ; 14(1): 11933, 2024 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789576

RESUMO

It is hypothesized that disparate brain regions interact via synchronous activity to control behavior. The nature of these interconnected ensembles remains an area of active investigation, and particularly the role of high frequency synchronous activity in simplistic behavior is not well known. Using intracranial electroencephalography, we explored the spectral dynamics and network connectivity of sensorimotor cortical activity during a simple motor task in seven epilepsy patients. Confirming prior work, we see a "spectral tilt" (increased high-frequency (HF, 70-100 Hz) and decreased low-frequency (LF, 3-33 Hz) broadband oscillatory activity) in motor regions during movement compared to rest, as well as an increase in LF synchrony between these regions using time-resolved phase-locking. We then explored this phenomenon in high frequency and found a robust but opposite effect, where time-resolved HF broadband phase-locking significantly decreased during movement. This "connectivity tilt" (increased LF synchrony and decreased HF synchrony) displayed a graded anatomical dependency, with the most robust pattern occurring in primary sensorimotor cortical interactions and less robust pattern occurring in associative cortical interactions. Connectivity in theta (3-7 Hz) and high beta (23-27 Hz) range had the most prominent low frequency contribution during movement, with theta synchrony building gradually while high beta having the most prominent effect immediately following the cue. There was a relatively sharp, opposite transition point in both the spectral and connectivity tilt at approximately 35 Hz. These findings support the hypothesis that task-relevant high-frequency spectral activity is stochastic and that the decrease in high-frequency synchrony may facilitate enhanced low frequency phase coupling and interregional communication. Thus, the "connectivity tilt" may characterize behaviorally meaningful cortical interactions.


Assuntos
Movimento , Córtex Sensório-Motor , Humanos , Masculino , Feminino , Adulto , Córtex Sensório-Motor/fisiologia , Córtex Sensório-Motor/fisiopatologia , Movimento/fisiologia , Adulto Jovem , Eletroencefalografia , Rede Nervosa/fisiologia , Epilepsia/fisiopatologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-38628954

RESUMO

This paper reports a microfabricated triaxial capacitive force sensor. The sensor is fully encapsulated with inert and biocompatible glass (fused silica) material. The sensor comprises two glass plates, on which four capacitors are located. The sensor is intended for subdermal implantation in fingertips and palms and providing tactile sensing capabilities for patients with paralyzed hands. Additional electronic components, such as passives and IC chips, can also be integrated with the sensor in a hermetic glass package to achieve an implantable tactile sensing system. Through attachment to a human palm, the sensor has been shown to respond appropriately to typical hand actions, such as squeezing or picking up a bottle.

4.
Pediatr Emerg Care ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38471748

RESUMO

OBJECTIVES: Rates of cannabis ingestion among young children are increasing. Small studies have evaluated symptomatology of these children. The literature lacks research regarding factors influencing medical management. Our goal was to 1) understand circumstances leading to exposure over time and 2) gain insight into factors that may influence emergency room management and Child Protective Services reporting over time. METHODS: Retrospective cross-sectional study on children younger than 10 years with cannabis-positive urine drug screens in the emergency room setting. Single-factor analysis of variance and Fisher exact tests were used to assess for trends. Two-tailed t tests and Fisher exact tests were used to compare management of children presenting to the emergency room with chief complaint (CC) "ingestion" versus those without. RESULTS: Of the 179 children, the mean age was 3.7 years and 48% were boys. We observed a significant increase over time in cannabis-positive children. The most common location of exposure was the primary residence (54%), with parents as the most frequent users (46%). In the emergency department, the most common CC was ingestion followed by altered mental status and fatigue. Children with an "ingestion" CC were managed with less testing than those with other CCs. They received fewer needle sticks (43% vs 91%), less imaging (5% vs 56% computed tomography heads), and fewer procedures (0% vs 8% lumbar punctures). Children with "ingestion" CC were less likely to be reported to Child Protective Services. CONCLUSIONS: Pediatric cannabis exposures are increasing and have a wide array of clinical presentations that complicate emergency room management. Parental report of cannabis ingestion seems to impact and reduce potentially unnecessary testing.

5.
Radiology ; 310(3): e231877, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38441098

RESUMO

Background Prostatic artery embolization (PAE) is a safe, minimally invasive angiographic procedure that effectively treats benign prostatic hyperplasia; however, PAE-related patient radiation exposure and associated risks are not completely understood. Purpose To quantify radiation dose and assess radiation-related adverse events in patients who underwent PAE at multiple centers. Materials and Methods This retrospective study included patients undergoing PAE for any indication performed by experienced operators at 10 high-volume international centers from January 2014 to May 2021. Patient characteristics, procedural and radiation dose data, and radiation-related adverse events were collected. Procedural radiation effective doses were calculated by multiplying kerma-area product values by an established conversion factor for abdominopelvic fluoroscopy-guided procedures. Relationships between cumulative air kerma (CAK) or effective dose and patient body mass index (BMI), fluoroscopy time, or radiation field area were assessed with linear regression. Differences in radiation dose stemming from radiopaque prostheses or fluoroscopy unit type were assessed using two-sample t tests and Wilcoxon rank sum tests. Results A total of 1476 patients (mean age, 69.9 years ± 9.0 [SD]) were included, of whom 1345 (91.1%) and 131 (8.9%) underwent the procedure with fixed interventional or mobile fluoroscopy units, respectively. Median procedure effective dose was 17.8 mSv for fixed interventional units and 12.3 mSv for mobile units. CAK and effective dose both correlated positively with BMI (R2 = 0.15 and 0.17; P < .001) and fluoroscopy time (R2 = 0.16 and 0.08; P < .001). No radiation-related 90-day adverse events were reported. Patients with radiopaque implants versus those without implants had higher median CAK (1452 mGy [range, 900-2685 mGy] vs 1177 mGy [range, 700-1959 mGy], respectively; P = .01). Median effective dose was lower for mobile than for fixed interventional systems (12.3 mSv [range, 8.5-22.0 mSv] vs 20.4 mSv [range, 13.8-30.6 mSv], respectively; P < .001). Conclusion Patients who underwent PAE performed with fixed interventional or mobile fluoroscopy units were exposed to a median effective radiation dose of 17.8 mSv or 12.3 mSv, respectively. No radiation-related adverse events at 90 days were reported. © RSNA, 2024 See also the editorial by Mahesh in this issue.


Assuntos
Embolização Terapêutica , Hiperplasia Prostática , Exposição à Radiação , Humanos , Masculino , Idoso , Hiperplasia Prostática/diagnóstico por imagem , Hiperplasia Prostática/terapia , Estudos Retrospectivos , Próstata/diagnóstico por imagem , Artérias/diagnóstico por imagem
6.
Plant Environ Interact ; 5(2): e10136, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38476212

RESUMO

Tropical forest phenology directly affects regional carbon cycles, but the relation between species-specific and whole-canopy phenology remains largely uncharacterized. We present a unique analysis of historical tropical tree phenology collected in the central Congo Basin, before large-scale impacts of human-induced climate change. Ground-based long-term (1937-1956) phenological observations of 140 tropical tree species are recovered, species-specific phenological patterns analyzed and related to historical meteorological records, and scaled to characterize stand-level canopy dynamics. High phenological variability within and across species and in climate-phenology relationships is observed. The onset of leaf phenophases in deciduous species was triggered by drought and light availability for a subset of species and showed a species-specific decoupling in time along a bi-modal seasonality. The majority of the species remain evergreen, although central African forests experience relatively low rainfall. Annually a maximum of 1.5% of the canopy is in leaf senescence or leaf turnover, with overall phenological variability dominated by a few deciduous species, while substantial variability is attributed to asynchronous events of large and/or abundant trees. Our results underscore the importance of accounting for constituent signals in canopy-wide scaling and the interpretation of remotely sensed phenology signals.

7.
Scand J Med Sci Sports ; 34(3): e14581, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38511417

RESUMO

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC's "no presumption of advantage" principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC's concept of "meaningful competition" is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports.


Assuntos
Medicina Esportiva , Esportes , Feminino , Humanos , Masculino , Identidade de Gênero , Atletas , Testosterona
8.
J Vasc Interv Radiol ; 35(4): 541-547, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38103863

RESUMO

PURPOSE: To compare prostatic artery embolization (PAE) via transradial access (TRA-PAE) versus transfemoral access (TFA-PAE) to assist access selection. MATERIAL AND METHODS: Procedural outcomes and adverse events were evaluated in 998 patients who underwent PAE at a single center from April 2014 to August 2022; 821 (82%) underwent TRA-PAE (Group R) and 177 (18%) underwent TFA-PAE (Group F). Mean age and prostate size of Groups R and F were 69.2 years (SD ± 8.4) and 117.4 g (SD ± 63.1) and 75.2 years (SD ± 12.1) and 127.2 g (SD ± 83.6), respectively (P < .01 and P = .16; postpropensity matching: P = .38 and P = .35, respectively). Indications for PAE included lower urinary tract symptoms, acute or chronic urinary retention, and hematuria. Procedural and patient-specific metrics were reviewed. Technical success was defined as bilateral PAE. Adverse events were recorded according to the Society of Interventional Radiology (SIR) adverse events classification. Statistical significance was defined as P < .05. RESULTS: Technical success was achieved in 798 (97.2%) patients in Group R and 165 (93.2%) patients in Group F. Mean procedural time, single- and continuous-rotation fluoroscopy time, dose area product, and air kerma were significantly lower in Group R than in Group F (P < .001). Moreover, 6 (0.7%) patients in Group R and 9 (5.5%) patients in Group F had access site ecchymoses, whereas 5 (0.6%) patients in Group R and 6 (3.6%) in Group F had access site hematomas. Two patients experienced transient ischemic attacks (TIAs) after TRA-PAE and recovered without intervention. Two occult radial artery occlusions were noted, but no patient experienced hand ischemia. CONCLUSIONS: In a large single interventional radiologist cohort, TRA-PAE demonstrated similar technical success to that of TFA-PAE with lower access site hemorrhagic complications and radiation requirements; however, TIA and occult radial artery occlusions remain a concern.


Assuntos
Embolização Terapêutica , Hiperplasia Prostática , Masculino , Humanos , Embolização Terapêutica/efeitos adversos , Próstata/irrigação sanguínea , Artéria Femoral/diagnóstico por imagem , Hiperplasia Prostática/diagnóstico por imagem , Hiperplasia Prostática/terapia , Resultado do Tratamento , Artéria Radial/diagnóstico por imagem , Estudos Retrospectivos
9.
Nat Plants ; 9(12): 1978-1985, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38036621

RESUMO

For long-lived organisms, investment in insurance strategies such as reserve energy storage can enable resilience to resource deficits, stress or catastrophic disturbance. Recent fire in California damaged coast redwood (Sequoia sempervirens) groves, consuming all foliage on some of the tallest and oldest trees on Earth. Burned trees recovered through resprouting from roots, trunk and branches, necessarily supported by nonstructural carbon reserves. Nonstructural carbon reserves can be many years old, but direct use of old carbon has rarely been documented and never in such large, old trees. We found some sprouts contained the oldest carbon ever observed to be remobilized for growth. For certain trees, simulations estimate up to half of sprout carbon was acquired in photosynthesis more than 57 years prior, and direct observations in sapwood show trees can access reserves at least as old. Sprouts also emerged from ancient buds-dormant under bark for centuries. For organisms with millennial lifespans, traits enabling survival of infrequent but catastrophic events may represent an important energy sink. Remobilization of decades-old photosynthate after disturbance demonstrates substantial amounts of nonstructural carbon within ancient trees cycles on slow, multidecadal timescales.


Assuntos
Incêndios , Sequoia , Árvores , Carbono , Fotossíntese
10.
Int J Drug Policy ; 121: 104195, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37778131

RESUMO

This article aims to excavate the lived experience of suffering with steroid-induced erectile dysfunction. By drawing upon original qualitative data, we chart the subjective journey to recovery of a male powerlifter and draw attention to the potential dangers of a self-help approach to treatment. Erectile dysfunction is a common symptom of anabolic-androgenic steroid-induced hypogonadism, a condition not commonly reported or discussed and is therefore a poorly studied health issue. Often considered a taboo subject, detailed accounts of men's experience of erectile dysfunction are relatively sparce, and so this paper makes an important contribution to bolstering what is a limited literature base. Links between contemporary conceptions of masculinity, muscularity, and sexual prowess are explored and form the basis of a critical analysis of popular treatment and prevention strategies. Among the central findings, this article suggests that steroids are not consumed despite the well-known risks, but precisely because the risks are well-known and ostensibly mitigated through engagement with 'bro-science'. We conclude that there is a concerning misalignment in current treatment and prevention strategies that needs to be addressed if the issue of non-prescribed steroid use is to be effectively tackled. This research therefore raises serious questions for the healthcare profession and its approach towards treating and preventing steroid consumption.


Assuntos
Disfunção Erétil , Masculino , Humanos , Disfunção Erétil/induzido quimicamente , Disfunção Erétil/tratamento farmacológico , Estudos Retrospectivos , Comportamento Sexual , Masculinidade , Esteroides/efeitos adversos
11.
Sports (Basel) ; 11(10)2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37888528

RESUMO

E-cycling is a growing area of cycling appealing to competitive cyclists and fitness enthusiasts. Zwift is the most popular e-cycling platform, with approx. 1 million subscribers and is a virtual environment that hosts regular races, including the UCI e-cycling world championships. The popularity of Zwift has given rise to cases of cheating and hacking the system to gain an advantage in e-racing. As a result, some high-profile professional riders have faced bans. We set out to understand the thoughts and concerns e-cyclists have about cheating, hacking, and doping in e-cycling. A total of 337 females and 1130 males were recruited over a 7-week period via social networking sites to complete an online survey. Forty-four per cent had experienced cheating during e-racing, which made them feel angry, annoyed, disappointed, and cheated. However, 15% of those who experienced cheating said they did not care, possibly because many see e-racing as a game or training tool rather than a competitive event. Eighty-seven per cent of participants were in favour of enforcing a ban on cheaters in e-cycling, while 34% wanted cheaters to be banned during in-person cycling events too. Results indicate that many e-cyclists have experienced cheating and would like clearer rules and bans for cheaters during e-races.

12.
Microsyst Nanoeng ; 9: 130, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37829157

RESUMO

The sense of touch is critical to dexterous use of the hands and thus an essential component of efforts to restore hand function after amputation or paralysis. Prosthetic systems have addressed this goal with wearable tactile sensors. However, such wearable sensors are suboptimal for neuroprosthetic systems designed to reanimate a patient's own paralyzed hand. Here, we developed an implantable tactile sensing system intended for subdermal placement. The system is composed of a microfabricated capacitive pressure sensor, a custom integrated circuit supporting wireless powering and data transmission, and a laser-fused hermetic silica package. The miniature device was validated through simulations, benchtop assessment, and testing in a primate hand. The sensor implanted in the fingertip accurately measured applied skin forces with a resolution of 4.3 mN. The output from this novel sensor could be encoded in the brain with microstimulation to provide tactile feedback. More broadly, the materials, system design, and fabrication approach establish new foundational capabilities for various applications of implantable sensing systems.

13.
Sci Data ; 10(1): 691, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37821473

RESUMO

Land surface phenology (LSP) products are currently of large uncertainties due to cloud contaminations and other impacts in temporal satellite observations and they have been poorly validated because of the lack of spatially comparable ground measurements. This study provided a reference dataset of gap-free time series and phenological dates by fusing the Harmonized Landsat 8 and Sentinel-2 (HLS) observations with near-surface PhenoCam time series for 78 regions of 10 × 10 km2 across ecosystems in North America during 2019 and 2020. The HLS-PhenoCam LSP (HP-LSP) reference dataset at 30 m pixels is composed of: (1) 3-day synthetic gap-free EVI2 (two-band Enhanced Vegetation Index) time series that are physically meaningful to monitor the vegetation development across heterogeneous levels, train models (e.g., machine learning) for land surface mapping, and extract phenometrics from various methods; and (2) four key phenological dates (accuracy ≤5 days) that are spatially continuous and scalable, which are applicable to validate various satellite-based phenology products (e.g., global MODIS/VIIRS LSP), develop phenological models, and analyze climate impacts on terrestrial ecosystems.

14.
Plant Environ Interact ; 4(4): 188-200, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37583877

RESUMO

Predicting vegetation phenology in response to changing environmental factors is key in understanding feedbacks between the biosphere and the climate system. Experimental approaches extending the temperature range beyond historic climate variability provide a unique opportunity to identify model structures that are best suited to predicting phenological changes under future climate scenarios. Here, we model spring and autumn phenological transition dates obtained from digital repeat photography in a boreal Picea-Sphagnum bog in response to a gradient of whole ecosystem warming manipulations of up to +9°C, using five years of observational data. In spring, seven equally best-performing models for Larix utilized the accumulation of growing degree days as a common driver for temperature forcing. For Picea, the best two models were sequential models requiring winter chilling before spring forcing temperature is accumulated. In shrub, parallel models with chilling and forcing requirements occurring simultaneously were identified as the best models. Autumn models were substantially improved when a CO2 parameter was included. Overall, the combination of experimental manipulations and multiple years of observations combined with variation in weather provided the framework to rule out a large number of candidate models and to identify best spring and autumn models for each plant functional type.

15.
New Phytol ; 240(1): 92-104, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37430467

RESUMO

Shifts in the age or turnover time of non-structural carbohydrates (NSC) may underlie changes in tree growth under long-term increases in drought stress associated with climate change. But NSC responses to drought are challenging to quantify, due in part to large NSC stores in trees and subsequently long response times of NSC to climate variation. We measured NSC age (Δ14 C) along with a suite of ecophysiological metrics in Pinus edulis trees experiencing either extreme short-term drought (-90% ambient precipitation plot, 2020-2021) or a decade of severe drought (-45% plot, 2010-2021). We tested the hypothesis that carbon starvation - consumption exceeding synthesis and storage - increases the age of sapwood NSC. One year of extreme drought had no impact on NSC pool size or age, despite significant reductions in predawn water potential, photosynthetic rates/capacity, and twig and needle growth. By contrast, long-term drought halved the age of the sapwood NSC pool, coupled with reductions in sapwood starch concentrations (-75%), basal area increment (-39%), and bole respiration rates (-28%). Our results suggest carbon starvation takes time, as tree carbon reserves appear resilient to extreme disturbance in the short term. However, after a decade of drought, trees apparently consumed old stored NSC to support metabolism.


Assuntos
Carbono , Pinus , Carbono/metabolismo , Pinus/fisiologia , Secas , Carboidratos/química , Amido/metabolismo , Árvores/fisiologia , Metabolismo dos Carboidratos
17.
Res Sq ; 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36778258

RESUMO

The sense of touch is critical to dexterous use of the hands and thus an essential component to efforts to restore hand function after amputation or paralysis. Prosthetic systems have focused on wearable tactile sensors. But wearable sensors are suboptimal for neuroprosthetic systems designed to reanimate a patient's own paralyzed hand. Here, we developed an implantable tactile sensing system intended for subdermal placement. The system is composed of a microfabricated capacitive force sensor, a custom integrated circuit supporting wireless powering and data transmission, and a laser-fused hermetic silica package. The miniature device was validated through simulations, benchtop testing, and ex vivo testing in a primate hand. The sensor implanted in the fingertip accurately measured skin forces with a resolution of 4.3 mN. The output from this novel sensor could be encoded in the brain with microstimulation to provide tactile feedback. More broadly, the materials, system design, and fabrication approach establish new foundational capabilities for various applications of implantable sensing systems.

18.
JAMA Netw Open ; 6(2): e2254069, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36757698

RESUMO

Importance: Understanding the causes of infant mortality shapes public health, surveillance, and research investments. However, the association of single-locus (mendelian) genetic diseases with infant mortality is poorly understood. Objective: To determine the association of genetic diseases with infant mortality. Design, Setting, and Participants: This cohort study was conducted at a large pediatric hospital system in San Diego County (California) and included 546 infants (112 infant deaths [20.5%] and 434 infants [79.5%] with acute illness who survived; age, 0 to 1 year) who underwent diagnostic whole-genome sequencing (WGS) between January 2015 and December 2020. Data analysis was conducted between 2015 and 2022. Exposure: Infants underwent WGS either premortem or postmortem with semiautomated phenotyping and diagnostic interpretation. Main Outcomes and Measures: Proportion of infant deaths associated with single-locus genetic diseases. Results: Among 112 infant deaths (54 girls [48.2%]; 8 [7.1%] African American or Black, 1 [0.9%] American Indian or Alaska Native, 8 [7.1%] Asian, 48 [42.9%] Hispanic, 1 [0.9%] Native Hawaiian or Pacific Islander, and 34 [30.4%] White infants) in San Diego County between 2015 and 2020, single-locus genetic diseases were the most common identifiable cause of infant mortality, with 47 genetic diseases identified in 46 infants (41%). Thirty-nine (83%) of these diseases had been previously reported to be associated with childhood mortality. Twenty-eight death certificates (62%) for 45 of the 46 infants did not mention a genetic etiology. Treatments that can improve outcomes were available for 14 (30%) of the genetic diseases. In 5 of 7 infants in whom genetic diseases were identified postmortem, death might have been avoided had rapid, diagnostic WGS been performed at time of symptom onset or regional intensive care unit admission. Conclusions and Relevance: In this cohort study of 112 infant deaths, the association of genetic diseases with infant mortality was higher than previously recognized. Strategies to increase neonatal diagnosis of genetic diseases and immediately implement treatment may decrease infant mortality. Additional study is required to explore the generalizability of these findings and measure reduction in infant mortality.


Assuntos
Mortalidade Infantil , Sequenciamento Completo do Genoma , Criança , Feminino , Humanos , Lactente , Recém-Nascido , Causalidade , Estudos de Coortes , Morte do Lactente , Masculino , California/epidemiologia
19.
Tree Physiol ; 2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36738259

RESUMO

Radiocarbon (∆14C) measurements of nonstructural carbon enable inference on the age and turnover time of stored photosynthate (e.g., sugars, starch), of which the largest pool in trees resides in the main bole. Because of potential issues with extraction-based methods, we introduce an incubation method to capture the ∆14C of nonstructural carbon via respired CO2. In this study, we compared the ∆14C obtained from these incubations with ∆14C from a well-established extraction method, using increment cores from a mature trembling aspen (Populus tremuloides). To understand any potential ∆14C disagreement, the yields from both methods were also benchmarked against the phenol-sulfuric acid concentration assay. We found incubations captured less than 100% of measured sugar and starch carbon, with recovery ranging from ~ 3% in heartwood to 85% in shallow sapwood. However, extractions universally over-yielded (mean 273 ± 101% expected sugar carbon; as high as 480%), where sugars represented less than half of extracted soluble carbon, indicating very poor specificity. While separation of soluble and insoluble nonstructural carbon is ostensibly a strength of extraction based methods, there was also evidence of poor separation of these two fractions in extractions. The ∆14C of respired CO2 and ∆14C from extractions were similar in the sapwood, while extractions resulted in comparatively higher ∆14C (older carbon) in heartwood and bark. Because yield and ∆14C discrepancies were largest in old tissues, incubations may better capture the ∆14C of nonstructural carbon that is actually metabolically available. That is, we suggest extractions include metabolically irrelevant carbon from dead tissues or cells, as well as carbon that is neither sugar nor starch. In contrast, nonstructural carbon captured by extractions must be respired to be measured. We thus suggest incubations of live tissues are a potentially viable, inexpensive, and versatile method to study the ∆14C of metabolically relevant (available) nonstructural carbon.

20.
Ann Vasc Surg ; 89: 166-173, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36328348

RESUMO

BACKGROUND: The spleen is the most commonly injured visceral organ in blunt abdominal trauma. Post-splenectomy infection risk has led to the shift toward spleen preserving procedures and splenic artery embolization (SAE) is now the treatment of choice for hemodynamically stable patients with splenic injury. This study aims to assess the long-term effect of SAE on splenic volume and platelet count. MATERIALS AND METHODS: Using CPT codes, 66 patients who underwent SAE were identified, and 14 of those who had the necessary imaging and laboratory follow-up were included in the study. Indications for SAE were portal hypertension in 8 patients, bleeding in 4 patients, and thrombocytopenia in 1, and one patient had a separate indication. Splenic volume was calculated by automated volumetric software (Aquarius, TeraRecon, Inc.). Paired t-tests were performed to compare splenic volume and platelets before and after SAE. RESULTS: Fourteen patients (7 males, 7 females) with a mean age of 51 ± 11.95 years underwent SAE and were followed by a repeat computed tomography scan at an average of 733.57 days. Nine SAEs were performed using vascular plugs, 3 using micro coils, and 2 out of that were with Gelfoam slurry, and 2 using coils only. All embolizations were technically successful with complete cessation of flow. Mean splenic volumes pre- and post-SAE were 903.5 ± 523.73 cm3 and 746.5 ± 511.95 cm3, respectively, representing a mean decrease of 8.31% compared to baseline [P = 0.346]. Minimum platelet counts (x103) pre-SAE (within 3 months) and post-SAE (2 weeks to 3 months after the procedure) were 55.79 ± 57.11 and 116 ± 145.40, respectively. The minimum platelet count showed a statistically significant mean increase of 134.92% (P = 0.033). CONCLUSIONS: The splenic volume is not altered significantly by SAE in the long term. Similarly, the platelet count is also not significantly altered at 3 months follow-up. This study, although small, suggests that SAE is a safe intervention that can preserve splenic volume and function in the long term.


Assuntos
Embolização Terapêutica , Ferimentos não Penetrantes , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Baço/diagnóstico por imagem , Baço/irrigação sanguínea , Baço/lesões , Contagem de Plaquetas , Artéria Esplênica/diagnóstico por imagem , Resultado do Tratamento , Estudos Retrospectivos , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/métodos , Ferimentos não Penetrantes/diagnóstico por imagem , Ferimentos não Penetrantes/terapia , Ferimentos não Penetrantes/etiologia
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