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1.
Am J Obstet Gynecol ; 230(5): 473-475, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38431464

RESUMO

Ninety-four percent of global maternal deaths occur in low- and middle-income countries (LMICs). The UN has a goal of reducing maternal deaths to <70 per 100,000 live births by 2030, but progress is minimal. Maternal deaths in LMICs are associated with 3 delays in the care of women with obstetrical emergencies: 1) in the family of the woman realizing that her life is at risk, 2) in the transport of the woman to a hospital, and 3) in providing care after arrival at the hospital. These 3 delays function like links in a chain, and failure of any link leads to maternal death. LMICs have characteristics that make it likely that the chain will break. Women in LMICs frequently have low standing, and cultural beliefs often lead to delay in the recognition of obstetrical emergencies. LMICs are characterized by poor roads and long distances to hospitals leading to transport delays. Cultural and other factors also lead to treatment delays when a woman reaches a suitably-equipped and staffed hospital. Nepal has addressed these delays and reduced maternal mortality. Firstly, we have reported in the Journal the use of culturally acceptable approaches to improving the knowledge about antenatal care in remote villages. In the case of Nepal, singing songs related to maternal care proved to be a highly effective strategy. We now report that the government of Nepal has repurposed military helicopters to overcome the tyranny of poor roads to allow rapid transport of women with obstetrical emergencies to a small number of fully-equipped and staffed hospitals. As of June 2023, this service has successfully retrieved 625 women in four and half years. The Nepalese government has included questions on maternal mortality in the 2021 national census, followed by a verbal autopsy. These data indicate a fall in the maternal mortality ratio from 239 in 2016 to 151 in 2021. The efficiency of the triage service continues to improve, suggesting that maternal mortality will continue to fall. This may provide a model that can be implemented in other LMICs and highlights factors that may be responsible for recent increases in the US maternal mortality ratio.


Assuntos
Países em Desenvolvimento , Mortalidade Materna , Humanos , Nepal/epidemiologia , Feminino , Gravidez , Resgate Aéreo , Tempo para o Tratamento , Complicações na Gravidez/mortalidade
2.
Glob Chang Biol ; 29(11): 2893-2925, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36802124

RESUMO

Although our observing capabilities of solar-induced chlorophyll fluorescence (SIF) have been growing rapidly, the quality and consistency of SIF datasets are still in an active stage of research and development. As a result, there are considerable inconsistencies among diverse SIF datasets at all scales and the widespread applications of them have led to contradictory findings. The present review is the second of the two companion reviews, and data oriented. It aims to (1) synthesize the variety, scale, and uncertainty of existing SIF datasets, (2) synthesize the diverse applications in the sector of ecology, agriculture, hydrology, climate, and socioeconomics, and (3) clarify how such data inconsistency superimposed with the theoretical complexities laid out in (Sun et al., 2023) may impact process interpretation of various applications and contribute to inconsistent findings. We emphasize that accurate interpretation of the functional relationships between SIF and other ecological indicators is contingent upon complete understanding of SIF data quality and uncertainty. Biases and uncertainties in SIF observations can significantly confound interpretation of their relationships and how such relationships respond to environmental variations. Built upon our syntheses, we summarize existing gaps and uncertainties in current SIF observations. Further, we offer our perspectives on innovations needed to help improve informing ecosystem structure, function, and service under climate change, including enhancing in-situ SIF observing capability especially in "data desert" regions, improving cross-instrument data standardization and network coordination, and advancing applications by fully harnessing theory and data.


Assuntos
Ecossistema , Fotossíntese , Clorofila , Fluorescência , Estações do Ano
3.
J Paediatr Child Health ; 59(4): 680-685, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36799108

RESUMO

AIM: High-risk neonates are retrieved from regional centres to tertiary neonatal units when the required care of the baby exceeds the clinical capabilities of the birthing facility. However, there is limited research on the outcomes of neonatal retrievals from regional special care centres and the barriers to back transfer of neonates from a tertiary centre are not well established. This study aimed to review the outcome of neonatal retrievals >32 weeks gestation from a regional referral centre. The study also aimed to determine missed opportunities for providing care at the regional centre and evaluate patient back transfer delays. METHODS: All neonates transferred to a tertiary neonatal intensive care unit in North Queensland over the 5-year period January 2016 to December 2020 from a regional neonatal centre were retrospectively reviewed from the electronic medical records. RESULTS: Fifty neonates transferred to a tertiary neonatal intensive care unit over the study period were identified. Between 2016 and 2020, the number of neonatal retrievals increased (P = 0.021). Out of the 50 neonatal retrievals, 86% were for medical reasons. Overall, eight neonates were identified as missed opportunities whose care could have been maintained at the regional centre with support from the tertiary neonatal intensive care unit. In total, 16 neonates were affected by a delay in back transfer. CONCLUSIONS: This study shows a significant increase in retrievals to tertiary neonatal intensive care unit over the study period. Increasing bed capacity, utilising telehealth and recruiting regional special care nursery staff could improve outcomes and reduce strain on tertiary neonatal resources.


Assuntos
Unidades de Terapia Intensiva Neonatal , Encaminhamento e Consulta , Recém-Nascido , Humanos , Estudos Retrospectivos , Queensland , Idade Gestacional
4.
Rev Geophys ; 56(2): 409-453, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30148283

RESUMO

The cloud droplet number concentration (N d) is of central interest to improve the understanding of cloud physics and for quantifying the effective radiative forcing by aerosol-cloud interactions. Current standard satellite retrievals do not operationally provide N d, but it can be inferred from retrievals of cloud optical depth (τ c) cloud droplet effective radius (r e) and cloud top temperature. This review summarizes issues with this approach and quantifies uncertainties. A total relative uncertainty of 78% is inferred for pixel-level retrievals for relatively homogeneous, optically thick and unobscured stratiform clouds with favorable viewing geometry. The uncertainty is even greater if these conditions are not met. For averages over 1° ×1° regions the uncertainty is reduced to 54% assuming random errors for instrument uncertainties. In contrast, the few evaluation studies against reference in situ observations suggest much better accuracy with little variability in the bias. More such studies are required for a better error characterization. N d uncertainty is dominated by errors in r e, and therefore, improvements in r e retrievals would greatly improve the quality of the N d retrievals. Recommendations are made for how this might be achieved. Some existing N d data sets are compared and discussed, and best practices for the use of N d data from current passive instruments (e.g., filtering criteria) are recommended. Emerging alternative N d estimates are also considered. First, new ideas to use additional information from existing and upcoming spaceborne instruments are discussed, and second, approaches using high-quality ground-based observations are examined.

5.
Eur Spine J ; 26(6): 1699-1710, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28102447

RESUMO

PURPOSE: We aim to describe a mechanism of failure in magnetically controlled growth rods which are used for the correction of the early onset scoliosis. METHODS: This retrieval study involved nine magnetically controlled growth rods, of a single design, revised from five patients for metal staining, progression of scoliosis, swelling, fractured actuator pin, and final fusion. All the retrieved rods were radiographed and assessed macroscopically and microscopically for material loss. Two implants were further analysed using micro-CT scanning and then sectioned to allow examination of the internal mechanism. No funding was obtained to analyse these implants. There were no potential conflicts interests. RESULTS: Plain radiographs revealed that three out of nine retrieved rods had a fractured pin. All had evidence of surface degradation on the extendable telescopic rod. There was considerable corrosion along the internal mechanism. CONCLUSIONS: We found that a third of the retrieved magnetically controlled growth rods had failed due to pin fracture secondary to corrosion of the internal mechanism. We recommend that surgeons consider that any inability of magnetically controlled growth rods to distract may be due to corrosive debris building up inside the mechanism, thereby preventing normal function.


Assuntos
Pinos Ortopédicos , Remoção de Dispositivo , Falha de Prótese , Escoliose/cirurgia , Criança , Corrosão , Feminino , Humanos , Fenômenos Magnéticos , Masculino , Microscopia Eletrônica de Varredura , Estudos Retrospectivos , Coluna Vertebral/crescimento & desenvolvimento , Coluna Vertebral/cirurgia , Microtomografia por Raio-X
6.
J Shoulder Elbow Surg ; 26(3): 521-528, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27727057

RESUMO

BACKGROUND: Shoulder hemiarthroplasty is a viable treatment for shoulder arthritis, particularly if the natural glenoid is still intact. One of the most common reasons for revision surgery is glenoid erosion, where the cartilage or bone is worn. The aim of the current study was to analyze whether the metallic articular surface of retrieved shoulder hemiarthroplasty is different from new implants. We hypothesized that the surface roughness would increase as a result of the articulation and that metallic wear would be detectable on the implants. METHODS: Included were 13 retrieved and 3 new shoulder hemiarthroplasties. The surface roughness was measured on different sites of the surface (dome of the head and the rim). The implants were further measured using a coordinate measuring machine to gain information on volumetric wear and geometric alterations. The surface was analyzed with a scanning electron microscope to see marks of wear. RESULTS: Compared with new implants, the surface roughness on the retrievals was significantly increased. The roughness parameters within the retrieval group were generally higher at the dome of the head than at the rim; however, this difference was not significant. Apart from shape deviations caused by deformation of the retrievals, no volumetric wear was detectable on the heads. CONCLUSIONS: The current results indicate that the roughness of the surface of the implant and the shape changes occur in vivo and that the material incurs damaged caused by the articulation against the softer cartilage or bone. Increasing roughness of the humeral component may be one cause for glenoid erosion over time.


Assuntos
Remoção de Dispositivo , Hemiartroplastia , Prótese de Ombro , Idoso , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Reoperação , Articulação do Ombro/cirurgia
7.
J Arthroplasty ; 32(12): 3806-3814, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28844627

RESUMO

BACKGROUND: The degradation of ceramic femoral heads made of yttria-stabilized zirconia (Y-TZP) because of tetragonal-to-monoclinic phase transformation in vivo is well-described, whereas magnesia-stabilized zirconia (Mg-PSZ) ceramics resist phase transformation in a warm aqueous environment. The purpose of this study was to evaluate phase transformation, changes in surface topography, and roughness parameters, including changes in surface polarity and abrasiveness, among retrieved zirconia femoral heads. METHODS: A total of 69 Y-TZP and 86 Mg-PSZ-retrieved femoral heads were examined, with 5 never-implanted heads of each type as controls. Selected heads were scanned by x-ray diffraction, to measure % monoclinic phase. All heads were scanned by optical profilometry to find visual evidence of degradation and to measure surface roughness, surface polarity, and the functional roughness parameters. Monoclinic phase % and roughness data were plotted vs time in vivo. RESULTS: Visual evidence of phase transformation was observed among Y-TZP femoral heads, and some exhibited pitting. Y-TZP femoral heads roughened and become more abrasive in vivo, although those made by CeramTec exhibited less degradation than those by Morgan and Saint Gobain. In contrast, Mg-PSZ heads did not exhibit pitting, undergo phase transformation, or roughen in vivo, and retained a negative surface polarity. CONCLUSION: All Y-TZP femoral heads exhibited increased phase transformation with time in vivo, although not all Y-TZP heads exhibited catastrophic roughening. No phase transformation was observed on Mg-PSZ femoral heads after up to 19.2 years in vivo. The lack of degradation among Mg-PSZ retrievals suggests a lower wear potential in joint replacement.


Assuntos
Cabeça do Fêmur/cirurgia , Prótese de Quadril , Óxido de Magnésio/química , Desenho de Prótese , Falha de Prótese , Zircônio/química , Cerâmica , Feminino , Seguimentos , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Propriedades de Superfície , Difração de Raios X , Ítrio
8.
J Arthroplasty ; 32(11): 3533-3538, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28712796

RESUMO

BACKGROUND: Recent observations of specific metal damage patterns on retrieved total joint implants implied a cellular origin and was termed inflammatory cell-induced (ICI) corrosion. Although ICI corrosion continues to present a potential damage source for metallic biomaterials surfaces, an alternate source of some damage patterns may arise from electrosurgery instruments in total joint arthroplasty. METHODS: To characterize electrosurgically-induced damage patterns on metal implants, a model system of highly polished CoCrMo and Ti-6Al-4V disks and commercial electrosurgical generator was evaluated in various modes and power settings using monopolar and bipolar configurations. Surfaces were tested dry, wet with phosphate-buffered saline, or covered with known thicknesses of hydrated 5% agarose hydrogel. RESULTS: In all cases, surface damage was generated on both alloy surfaces, directly resulting from plasma discharge interacting with the metal. Direct surface contact caused pitting and oxide buildup at the contact area. Damage was produced through 3 mm thickness of hydrogel on the surface and across metal-metal junctions representing modular tapers. Damage patterns on wetted surfaces were highly consistent with damage patterns observed on retrieved total joint implants; circular, ruffled areas with centralized pits, occasionally presenting trail- and weld-like features. CONCLUSION: Surgeons using electrosurgical systems in proximity to metallic implants should exercise caution. Discharge of electrical energy through implants can induce localized surface damage and may result in other adverse outcomes. Although these results show some damage reported to be ICI corrosion is indeed the result of electrosurgery, there remains damage observed in retrievals not explained by this process.


Assuntos
Eletrocirurgia/efeitos adversos , Prótese Articular , Ligas , Artroplastia , Materiais Biocompatíveis , Corrosão , Humanos , Teste de Materiais , Ortopedia , Propriedades de Superfície , Titânio , Vitálio
9.
Int Orthop ; 41(12): 2495-2501, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28578471

RESUMO

PURPOSE: We aimed to assess polyethylene liners of retrieved hips of one design of a dual mobility (DM) cup liner and two designs of femoral stems to better understand the role of femoral stem design on polyethylene impingement. METHODS: This was a case-control study involving 70 retrieved highly cross-linked polyethylene (X3) liners used with ABGII (n = 35) and Rejuvenate (n = 35) stems (Stryker). All polyethylene liners were assessed for evidence of rim deformation and the damage quantified using metrology methods. RESULTS: A total of 80% of polyethylene liners paired with ABGII necks had macroscopic evidence of neck impingement resulting in a raised lip whilst 23% of liners paired with Rejuvenate necks had evidence of a raised lip (p < 0.0001). The height of the raised rims of the DM cups paired with ABGII necks had a median (range) of 139 µm (72-255). The height of the raised rims of the DM cups paired with Rejuvenate necks had a median (range) of 52 µm (45-90) (p < 0.0001). CONCLUSION: Our new findings from retrieved dual mobility bearings showed that polyethylene liner rim deformation resulting from impingement with the femoral neck occurs in early in-human function, is circumferential in distribution, and is affected by the stem neck design. We recommend the use of highly polished and non-edged neck designs when used in conjunction with DM cups.


Assuntos
Artroplastia de Quadril/instrumentação , Prótese de Quadril/efeitos adversos , Desenho de Prótese/efeitos adversos , Falha de Prótese/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Estudos de Casos e Controles , Feminino , Articulação do Quadril/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Polietileno/efeitos adversos , Fatores de Tempo , Microtomografia por Raio-X
10.
J Arthroplasty ; 31(7): 1595-602, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26796773

RESUMO

BACKGROUND: The objective of this study was to assess the retentive rim of retrieved dual mobility liners for visible evidence of deformation from femoral neck contact and to use cadaver models to determine if anterior soft tissue impingement could contribute to such deformation. METHODS: Fifteen surgically retrieved polyethylene liners were assessed for evidence of rim deformation. The average time in vivo was 31.4 months, and all patients were revised for reasons other than intraprosthetic dislocation. Liner interaction with the iliopsoas was studied visually and with fluoroscopy in cadaver specimens using a dual mobility system different than the retrieval study. For fluoroscopic visualization, a metal wire was sutured to the iliopsoas and wires were also embedded into grooves on the outer surface of the liner and the inner head. RESULTS: All retrievals showed evidence of femoral neck contact. The cadaver experiments showed that liner motion was impeded by impingement with the iliopsoas tendon in low flexion angles. When observing the hip during maximum hyperextension, 0°, 15°, and 30° of flexion, there was noticeable tenting of the iliopsoas caused by impingement with the liner. CONCLUSION: Liner rim deformation resulting from contact with the femoral neck likely begins during early in vivo function. The presence of deformation is indicative of a mechanism inhibiting mobility of the liner. The cadaver studies showed that liner motion could be impeded because of its impingement with the iliopsoas. Such soft tissue impingement may be one mechanism by which liner motion is routinely inhibited, which can result in load transfer from the neck to the rim.


Assuntos
Artroplastia de Quadril/métodos , Prótese de Quadril , Polietileno/química , Desenho de Prótese , Amplitude de Movimento Articular , Adulto , Idoso , Cadáver , Feminino , Colo do Fêmur , Fluoroscopia , Humanos , Luxações Articulares , Masculino , Metais , Pessoa de Meia-Idade , Falha de Prótese
11.
Horm Behav ; 73: 23-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26065732

RESUMO

The importance of maternal care on offspring development has received considerable attention, although more recently, researchers have begun to focus on the significance of paternal contributions. In the monogamous and bi-parental California mouse, fathers provide high levels of care, and therefore serve as a model system for studying paternal effects on behavior and underlying neuroendocrine mechanisms. Paternal retrievals in this species influence long term changes in brain (expression of arginine vasopressin-AVP) and behavior (aggression and parenting) in adult male offspring. Further, paternal retrievals induce a transient increase in testosterone (T) in male offspring, which is thought to mediate the relationship between paternal retrievals and AVP expression. Although the father-son relationship has been well characterized, few studies have examined father-daughter interactions. In California mice, paternal retrievals increase aggression in female offspring. Although T has been implicated in the regulation of female aggression, it remains unclear whether T may underlie long-term changes in female offspring aggression in response to paternal retrievals. In the current study, we examined the influence of paternal retrievals on T in both male and female offspring. Retrievals were manipulated experimentally by displacement of the pup and trunk blood was collected from retrieved, non-retrieved, and non-manipulated (baseline) pups. We found that fathers expressed similar levels of retrievals towards sons and daughters, and that T levels were elevated in retrieved, as compared to non-retrieved offspring. Similar to what has been previously described in male offspring and replicated here, female offspring that were retrieved had higher T levels than non-retrieved females. Neither females nor males experienced a change in corticosterone levels in response to retrievals suggesting offspring do not mount a stress response to paternal care. Therefore, our data suggest that paternal retrievals may serve similar functions in shaping adult behavior in both male and female offspring via modulation of hormone levels.


Assuntos
Comportamento Paterno/fisiologia , Peromyscus/fisiologia , Testosterona/sangue , Agressão/fisiologia , Animais , Arginina Vasopressina/metabolismo , Corticosterona/sangue , Pai , Feminino , Asseio Animal/fisiologia , Masculino , Comportamento de Nidação/fisiologia , Peromyscus/sangue
12.
J Arthroplasty ; 30(10): 1828-34, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26048729

RESUMO

The development of highly cross-linked UHMWPEs focused on stabilizing radiation-induced free radicals as the sole precursor to oxidative degradation. However, secondary in vivo oxidation mechanisms have been discovered. After a preliminary post-operative analysis, we subjected highly cross-linked retrievals with 1-4 years in vivo durations and never-implanted controls to accelerated aging to predict the extent to which their oxidative stability was compromised in vivo. Lipid absorption, oxidation, and hydroperoxides were measured using infrared spectroscopy. Gravimetric swelling was used to measure cross-link density. After aging, all retrievals, except vitamin E-stabilized components, regardless of initial lipid levels or oxidation, showed significant oxidative degradation, demonstrated by subsurface oxidative peaks, increased hydroperoxides and decreased cross-link density, compared to their post-operative material properties and never-implanted counterparts, confirming oxidative stability changes.


Assuntos
Reagentes de Ligações Cruzadas/química , Oxigênio/química , Polietilenos/química , Prótese de Quadril , Humanos , Prótese do Joelho , Lipídeos/química , Oxirredução , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Vitamina E/química
13.
J Orthop Res ; 42(4): 777-787, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37975250

RESUMO

Analysis of polyethylene (PE) wear in knee implants is crucial for understanding the factors leading to revision in total knee arthroplasty. Importantly, current experimental and computational methods for predicting insert wear can only be validated against true in vivo measurements from retrievals. This study quantitatively investigated in vivo PE wear rates in fixed-bearing (FB) (n = 21) and rotating-platform (n = 53) implant retrievals. 3D surface geometry of the retrievals was measured using a structured light scanner. Then, a reference surface that included the deformation, but not the wear that the retrievals had experienced in vivo, was constructed using a fully automatic surface reconstruction algorithm. Finally, wear volume was calculated from the deviation between the worn and reconstructed surfaces. The measurement and analysis techniques were validated and the algorithm was found to produce errors of only 0.2% relative to the component volumes. In addition to quantifying cohort-level wear rates, the effect of mechanical axis limb alignment on mediolateral wear distribution was examined for a subset of the retrievals (n = 14 + 26). Our results show that FB implants produce significantly (p = 0.04) higher topside wear rates (24.6 ± 10.1 mm3/year) than rotating-platform implants (15.3 ± 8.0 mm3/year). This effect was larger than that of limb alignment, which had a smaller and nonsignificant influence on overall wear rates (+4.5 ± 11.6 mm3/year, p = 0.43). However, increased varus alignment was associated significantly with greater medial compartment wear in both the FB and rotating-platform designs (+1.7 ± 1.3%/° and +1.8 ± 1.6%/°). Our findings emphasize the importance of implant design and limb alignment on wear outcomes, providing reference data for improving implant performance and longevity.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Humanos , Desenho de Prótese , Artroplastia do Joelho/métodos , Polietileno , Propriedades de Superfície , Articulação do Joelho/cirurgia , Falha de Prótese
14.
Sci Total Environ ; 950: 175355, 2024 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-39122047

RESUMO

The global increase in population has led to higher emissions from livestock and synthetic fertilizers. This study investigates the impact of agricultural ammonia emissions on NH3 concentrations and provides insights into PM2.5 levels and their components in agriculturally intensified areas. We developed a bottom-up emission inventory focused on fertilizer application over croplands and livestock, instead of relying on the EMEP database. This approach utilized an improved spatial and temporal distribution of these emissions. We compared annual total NH3 emissions from livestock and fertilizer, estimated at 598.5 kt and 187.2 kt in the EMEP inventory (Base case), and 245.2 kt and 536 kt in the bottom-up inventory (Scenario case). Using the CMAQ modelling framework, we estimated atmospheric concentrations for both cases and evaluated the model results by comparing them with IASI-NH3 satellite retrievals. This comparison revealed significant differences in column concentrations between the Base and Scenario cases, with the Scenario case showing substantial improvement. Over a period of seven months, which contributed 80 % of the annual agricultural emissions for the Scenario case, the domain averages of NH3 were 3.02 × 1015, 4.15 × 1015, and 4.17 × 1015 molecules/cm2 for the Base and Scenario cases and IASI-NH3, respectively. The Scenario case closely matched IASI measurements, indicating a more accurate representation of NH3 emissions and concentrations. This enhanced reliability underscores the effectiveness of the bottom-up inventory approach. Additionally, using the CMAQ model, we found that in the IASI hotspots, the averages were 1.67 µg/m3 for sulfate, 0.57 µg/m3 for nitrate, and 0.62 µg/m3 for ammonium, with a total PM2.5 mean of 10.45 µg/m3.

15.
Sci Total Environ ; 856(Pt 1): 158797, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36116651

RESUMO

A near-real-time (NRT) aerosol forecast and diagnostic approach is developed based on the system of Infusing satellite Data into Environmental Applications for East Asia, herein denoted as IDEA-EA. The design incorporates a 0.5-degree Global Forecast System (GFS) and Visible Infrared Imaging Radiometer Suite (VIIRS) aerosol and cloud retrievals for meteorological and remote sensing inputs. The primary output of IDEA-EA includes aerosol forward and backward air mass trajectory forecasts, migration visualization, and data synthesis purposed for NRT aerosol detection, monitoring, and source tracing in East Asia. Two aerosol episodes of Southeast Asia (SEA) biomass burning and Chinese haze infusion with Gobi dust are illustrated by IDEA-EA to demonstrate its forecast and source tracing capabilities. In the case of SEA biomass burning (late March 2021), forward trajectories of IDEA-EA forecasted air masses with high aerosol optical depth (AOD) from SEA affecting Taiwan. The IDEA-EA forecasts were verified by increased AOD and surface PM2.5 observations at a mountain site. In the case of the Chinese haze (October 30, 2019), backward trajectories from the northern tip of Taiwan traced air masses back to the east coast of mainland China and possibly further to the Gobi Desert. Compared with conventional numerical model simulations, the combination of the state-of-the-art aerosol remote sensing and trajectory modeling in IDEA-EA provides a cost-effective alternative for air quality management.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Aerossóis/análise , Poluição do Ar/análise , Poeira/análise
16.
Environ Sci Pollut Res Int ; 30(44): 100215-100232, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37632617

RESUMO

Impact of COrona VIrus Diseases 2019 (COVID-19) restrictive measures on aerosol optical depth (AOD) and black carbon (BC) concentration is investigated for the western, central, and eastern Indo-Gangetic Plain (IGP) using satellite-based observations. Due to COVID-19-induced lockdown measures, a noticeable decline in AOD and BC concentrations was observed across the IGP when compared to pre-lockdown period of 2020 and the lockdown concurrent period of 2015-2019. During the total lockdown period, a maximum drop in AOD and BC was observed in the central IGP (26.5 % and 10.1 %), followed by western IGP (24.9% and 5.2%) and eastern IGP (23.2 % and 4.9 %) with respect to the same period of 2015-2019. We have removed seasonal influences on aerosol properties during the COVID-19 lockdown, by taking average seasonal variations during the period of 2015-2019 as reference and projecting the hypothetical AOD and BC for the lockdown period under normal scenario. The difference between the hypothetical AOD and BC (under normal scenario) and the retrieved AOD and BC for the lockdown period is the absolute percentage change in AOD and BC concentration due to the lockdown alone. This elimination of seasonal influence is a novel approach. Central IGP showed an absolute decrease in AOD and BC of 38.5% and 18.2% during the lockdown period followed by western IGP (34.6% and 7.7%) and eastern IGP (25.9% and 11.5%). The observed absolute reduction in AOD, 26-39 %, is significantly higher than the global average reduction in AOD of 2-5%. CALIPSO-derived aerosol sub-types over major location of the western, central, and eastern IGP suggests prevalence of anthropogenic activities during pre- and post-lockdown periods. During the lockdown, IGP was influenced by aerosols from natural sources, with mineral dust and polluted dust in the western and central IGP, and aerosols from marine regions in the eastern IGP. Replenishment of aerosols within the boundary layer were far quicker when compared to total column during post-lockdown. Overall, the study reveals a reduction in anthropogenic emissions during the COVID-19-induced lockdowns, leading to temporary improvements in air quality over the IGP. Our study presents a comprehensive analysis of COVID-19 lockdown impact on aerosols properties over the IGP and highlights unprecedented reductions in AOD (~ 40 %) and BC (~ 20 %), due to imposition of lockdown and subsequent cessation of aerosol sources, by removing seasonal influences.


Assuntos
Poluentes Atmosféricos , COVID-19 , Humanos , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Controle de Doenças Transmissíveis , Aerossóis e Gotículas Respiratórios , Poeira/análise , Fuligem/análise , Índia
17.
Sci Total Environ ; 897: 165144, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37391145

RESUMO

Nitrogen dioxide (NO2) pollution remains a serious global problem, particularly near highly populated urbanized coasts that face increasing challenges with climate change. Yet, the combined impact of urban emissions, pollution transport, and complex meteorology on the spatiotemporal dynamics of NO2 along heterogeneous urban coastlines remains poorly characterized. Here, we integrated measurements from different platforms - boats, ground-based networks, aircraft, and satellites - to characterize total column NO2 (TCNO2) dynamics across the land-water continuum in the New York metropolitan area, the most populous area in the United States that often experiences the highest national NO2 levels. Measurements were conducted during the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS), with a main goal to extend surface measurements beyond the coastline - where ground-based air-quality monitoring networks abruptly stop - and over the aquatic environment where peaks in air pollution often occur. Satellite TCNO2 from TROPOMI correlated strongly with Pandora surface measurements (r = 0.87, N = 100) both over land and water. Yet, TROPOMI overall underestimated TCNO2 (MPD = -12%) and missed peaks in NO2 pollution caused by rush hour emissions or pollution accumulation during sea breezes. Aircraft retrievals were in excellent agreement with Pandora (r = 0.95, MPD = -0.3%, N = 108). Stronger agreement was found between TROPOMI, aircraft, and Pandora over land, while over water satellite, and to a lesser extent aircraft, retrievals underestimated TCNO2 particularly in the highly dynamic New York Harbor environment. Combined with model simulations, our shipborne measurements uniquely captured rapid transitions and fine-scale features in NO2 behavior across the New York City - Long Island Sound land-water continuum, driven by the complex interplay of human activity, chemistry, and local scale meteorology. These novel datasets provide critical information for improving satellite retrievals, enhancing air quality models, and informing management decisions, with important implications for the health of diverse communities and vulnerable ecosystems along this complex urban coastline.

18.
Front Neurosci ; 16: 1030702, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36685240

RESUMO

The retrieval of fear memories induces two opposing processes, reconsolidation, and extinction. The memory reconsolidation is an active process that involves gene expression and updates an existing memory. It is hypothesized that blockade of reconsolidation by manipulating the neurobiological factors, which are mechanistically involved in the process, could weaken or disrupt the original fear memory. The N-methyl-D-aspartate (NMDA) receptor and hippocampal neurogenesis play crucial roles in hippocampus-dependent memory processes, including reconsolidation. Using contextual fear conditioning paradigm with multiple retrievals, we attempted to weaken the original contextual fear memory by repeatedly disrupting retrieval-induced reconsolidation via downregulation of NMDA receptor signaling and inhibition of neurogenesis. In the first experiment, prior to fear conditioning, NMDA receptor signaling was downregulated by the genetic reduction of its co-agonist, D-serine, and the neurogenesis was dampened by focal X-ray irradiation on the hippocampus. We found that simultaneous D-serine reduction and neurogenesis dampening resulted in a progressive decrease in freezing following each retrieval, leading to an attenuation of remote contextual fear memory on day 28. In the second experiment using the same behavioral protocols, after conditioning, pharmacological approaches were conducted to simultaneously block D-serine signaling and neurogenesis, resulting in a similar suppressive effect on the remote fear memory. The present findings provide insights for understanding the role of D-serine-mediated NMDA receptor signaling and neurogenesis in memory retrieval and the maintenance of remote fear memory, and improving the efficacy of exposure-based therapy for the treatment of post-traumatic stress disorder (PTSD).

19.
Clin Neuroradiol ; 32(2): 353-360, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34191040

RESUMO

BACKGROUND AND PURPOSE: A Thrombolysis in Cerebral Infarction (TICI) score of 3 has been established as therapeutic goal in endovascular therapy (EVT) for acute ischemic stroke; however, in the case of early TICI2b reperfusion, the question remains whether to stop the procedure or to continue in the pursuit of perfection (i.e., TICI 2c/3). METHODS: A total of 6635 patients were screened from the German Stroke Registry. Patients who underwent EVT for occlusion of the middle cerebral artery (M1 segment), with final TICI score of 2b/3 were included. Multivariable logistic regression was performed with functional independence (modified Rankin Scale, mRS at day 90 of 0-2) as the dependent variable. RESULTS: Of 1497 patients, 586 (39.1%) met inclusion criteria with a final TICI score of 2b and 911 (60.9%) with a TICI score of 3. Patients who achieved first-pass TICI3 showed highest odds of functional independence (Odds ratio [OR] 1.71, 95% confidence interval [95% CI] 1.18-2.47). Patients who achieved TICI2b with the second pass (OR 0.53, 95% CI 0.31-0.89) or with three or more passes (OR 0.44, 95% CI 0.27-0.70) had significantly worse clinical outcomes compared to first-pass TICI2b. TICI3 at the second pass was by trend better than first-pass TICI2b (OR 1.55, 95% CI 0.98-2.45), but TICI3 after 3 or more passes (OR 0.93, 95% CI 0.57-1.50) was not significantly different from first-pass TICI2b. CONCLUSION: First-pass TICI2b was superior to TICI2b after ≥ 2 retrievals and comparable to TICI3 at ≥ 3 retrievals. The potential benefit in outcome after achieving TICI3 following further retrieval attempts after first-pass TICI2b need to be weighed against the risks.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Isquemia Encefálica/terapia , Infarto Cerebral , Procedimentos Endovasculares/métodos , Humanos , Reperfusão/métodos , Estudos Retrospectivos , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Resultado do Tratamento
20.
Sensors (Basel) ; 11(1): 341-61, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22346581

RESUMO

On-demand information retrieval enables users to query and collect up-to-date sensing information from sensor nodes. Since high energy efficiency is required in a sensor network, it is desirable to disseminate query messages with small traffic overhead and to collect sensing data with low energy consumption. However, on-demand query messages are generally forwarded to sensor nodes in network-wide broadcasts, which create large traffic overhead. In addition, since on-demand information retrieval may introduce intermittent and spatial data collections, the construction and maintenance of conventional aggregation structures such as clusters and chains will be at high cost. In this paper, we propose an on-demand information retrieval approach that exploits the name resolution of data queries according to the attribute and location of each sensor node. The proposed approach localises each query dissemination and enable localised data collection with maximised aggregation. To illustrate the effectiveness of the proposed approach, an analytical model that describes the criteria of sink proxy selection is provided. The evaluation results reveal that the proposed scheme significantly reduces energy consumption and improves the balance of energy consumption among sensor nodes by alleviating heavy traffic near the sink.


Assuntos
Armazenamento e Recuperação da Informação , Algoritmos , Modelos Teóricos , Tecnologia sem Fio
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