Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
iScience ; 26(11): 108123, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37876825

RESUMO

Previous heat risk assessments have limitations in obtaining accurate heat hazard sources and capturing population distributions, which change over time. This study proposes a diurnal heat risk assessment framework incorporating spatiotemporal air temperature and real-time population data. Daytime and nighttime heat risk maps were generated using hazard, exposure, and vulnerability components in Seoul during the summer of 2018. The hazard was derived from the daily extreme air temperatures obtained using the stacking machine learning model. Exposure was calculated using de facto population density, and vulnerability was assessed using demographic and socioeconomic indicators. The resulting maps revealed distinct diurnal spatial patterns, with high-risk areas in the urban core during the day and dispersed at night. Daytime heat risk was strongly correlated with heat-related illness ratios (R = 0.8) and accurately captured temporal fluctuations in heat-related illness incidence. The proposed framework can guide site-specific adaptation and response plans for dynamic urban heat events.

2.
Innovation (Camb) ; 4(5): 100481, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37636281

RESUMO

To achieve the Paris Agreement, China pledged to become "Carbon Neutral" by the 2060s. In addition to massive decarbonization, this would require significant changes in ecosystems toward negative CO2 emissions. The ability of coastal blue carbon ecosystems (BCEs), including mangrove, salt marsh, and seagrass meadows, to sequester large amounts of CO2 makes their conservation and restoration an important "nature-based solution (NbS)" for climate adaptation and mitigation. In this review, we examine how BCEs in China can contribute to climate mitigation. On the national scale, the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha, including over 75% as unvegetated tidal flats. The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year-1, of which most occurs in salt marshes and tidal flats. The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year-1 along the Chinese coastline. Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of $32,000 ha-1 year-1. The potential practices and technologies that can be implemented in China to improve BCE C sequestration, including their constraints and feasibility, are also outlined. Future directions are suggested to improve blue carbon estimates on aerial extent, carbon stocks, sequestration, and mitigation potential. Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

3.
Injury ; 53(4): 1552-1556, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35140028

RESUMO

BACKGROUND: Acute Achilles tendon rupture (AATR) is a common injury of the foot and ankle. So far, the optimal management of AATR remains controversial. The target of the present retrospective study was to describe a new operative technique for percutaneous repair of AATR and evaluate efficacy of the technique. METHODS: In the present study, 32 patients were enrolled with AATR treated with the percutaneous oval forceps suture-guiding method with anchor nails from Jan 2014 to Jan 2017. The operation duration and length of incision were collected. The functional outcomes were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, Achilles tendon total rupture score (ATRS), range of motion (ROM) of the ankle and plantar flexion strength ratio at the last follow-up. The postoperative sports activity level and complications were also recorded. RESULTS: The mean operation duration and length of incision were 24.5 min and 2.0 cm. Whilst patient reported outcome questionnaires like AOFAS and ATRS showed good results, ROM of the ankle was quite low with only 16.5 degrees. Plantar flexion strength ratio was lower post surgery, as well. As for the postoperative sports activity level: 26/32 cases (81.3%) returned to former sports activity level; 4/32 cases (12.5%) showed a decline in sports activity level; 2/32 cases (6.2%) gave up on sports. The overall complication rate was 6.2%, one sural nerve damage and one fusiform thickening were found in the study. CONCLUSION: The percutaneous oval forceps suture-guiding method with anchor nails is a new considerable surgery method with adequate healing rates and an alternative to existing surgical procedures.


Assuntos
Tendão do Calcâneo , Procedimentos Ortopédicos , Tendão do Calcâneo/lesões , Tendão do Calcâneo/cirurgia , Humanos , Unhas/cirurgia , Procedimentos Ortopédicos/métodos , Estudos Retrospectivos , Ruptura/etiologia , Ruptura/cirurgia , Instrumentos Cirúrgicos , Técnicas de Sutura , Suturas , Resultado do Tratamento
4.
Sci Total Environ ; 778: 146253, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721643

RESUMO

Traditional soil salinity studies are time-consuming and expensive, especially over large areas. This study proposed an innovative deep learning convolutional neural network (DL-CNN) data-driven approach for SSD mapping. Multi-spectral remote sensing data encompassing Landsat series images provide the possibility for frequent assessment of SSD in various regions of the world. Therefore, Landsat 7 ETM+ and 8 OLI images were acquired for years 2005, 2010, 2015 and 2019. Totally, 704 sample points collected from the top 20 cm of the soil surface, which 70% was used to train the network and the remains (30%) were utilized to validate the network. Accordingly, DL-CNN model trained using remote sensing (RS)-derived variables (land surface temperature (LST), Soil moisture (SM) and evapotranspiration) and geospatial data such as NDVI and landuse. To train the CNN, ReLu, Cross-entropy and ADAM were employed respectively as activation, loss/cost functions and optimizer. The results indicated the high confidence of OA 0.94.02, 0.93.99, 0.94.87 and 0.95.0 respectively for years 2005, 2010, 2015 and 2019. These accuracies demonstrated the best performance of automated DL-CNN for SSD mapping compared to RS soil salinity indexes. Furthermore, the FR and WOE models applied in order to generate a geospatial assessment of the DL-CNN classification results. According to the FR model, landuse, LST, LST and NDVI with the frequency ratio of 0.98.25, 0.94.03, 0.97.23 and 0.96.36 selected respectively as more effective factors for SSD in the study area for years 2005, 2010, 2015 and 2019. Also based on the WOE model, landuse, LST, landuse and NDVI with the WOE of 0.88.25, 0.91.88, 0.87.43 and 0.89.02 were ranked respectively for years 2005, 2010, 2015 and 2019 as efficient variables for SSD. In sum, our introduced method can be recommended for SDD spatial modelling in other favored areas with similar environmental conditions.

5.
Orthop Surg ; 13(2): 434-441, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33470058

RESUMO

OBJECTIVE: To investigate the therapeutic efficacy of titanium elastic intramedullary nail (TEN) and open reduction and internal fixation with plate (ORIF) in the treatment of humeral fracture in children. METHODS: A retrospective study was carried out in a total of 69 patients who were admitted to the hospital from January 2013 to December 2018. These patients, including 41 males and 28 females, were aged from 6 to 12 years old with a median of 8 years. These patients were diagnosed with humeral fracture and underwent the surgery of ORIF (n = 22) or TEN (n = 47). The intraoperative bleeding, operation time, length of stay (LOS), and fracture healing time were compared between the two groups. The therapeutic effect was assessed by the shoulder range of motion, the elbow range of motion, the UCLA shoulder function score, and the Mayo elbow performance score (MEPS) 6 months after the surgery. RESULTS: The intraoperative bleeding (97.20 ± 27.83 mL vs 185.60 ± 37.50 mL, P < 0.05), the operation time (53.70 ± 11.87 min vs 73.50 ± 13.33 min, P < 0.05), and the fracture healing time (9.30 ± 4.23 weeks vs 13.45 ± 3.67 weeks, P < 0.05) in the TEN group was significantly decreased than those in the ORIF group. There was no significant difference in the LOS between the two groups. The length of follow-up is 3 and 6 months. The shoulder range of motion (110.88° ± 15.82° vs 98.37° ± 16.22° at 3 months and 162.88° ± 17.29° vs 117.65° ± 19.38° at 6 months, both P < 0.05), the elbow range of motion (105.23° ± 2.81° vs 87.12° ± 4.73° at 3 months and 137.47° ± 4.82° vs 109.67° ± 5.83° at 6 months, both P < 0.05), and the UCLA shoulder function score (28.58 ± 4.74 vs 21.64 ± 7.23 at 3 months and 33.05 ± 3.27 vs 25.78 ± 3.87 at 6 months, both P < 0.05), and the MEPS (80.76 ± 3.53 vs 65.33 ± 9.43 at 3 months and 97.48 ± 1.23 vs 88.22 ± 3.65 at 6 months, both P < 0.05) in the TEN group were greater than those in the ORIF group. In the TEN group, complications occurred in three of 47 cases (6.38%), including one case (2.13%) of bone nonunion and two cases (4.25%) of irritation response around the nail. In the ORIF group, complications occurred in four of 22 cases (18.18%), including one case (4.55%) of delayed healing, one case (4.55%) of deep infection, and two cases (9.08%) of radial nerve injury. The complication rate was not significantly different between the two groups. CONCLUSION: TEN can be a good technique for the treatment of humeral fracture in children, with the advantages of less intraoperative bleeding, shorter operative time, quicker healing, and better recovery of shoulder range of motion and elbow range of motion.


Assuntos
Placas Ósseas , Fixação Interna de Fraturas/métodos , Fraturas do Úmero/cirurgia , Redução Aberta/métodos , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Titânio
6.
Sci Total Environ ; 763: 144224, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33383505

RESUMO

The surface urban heat island (SUHI) is one of the most significant human-induced alterations to the Earth's surface climate and can aggravate health risks for city dwellers during heat waves. Although the SUHI effect has received growing attention, its diurnal cycles (i.e., the variations over the full 24 h within the diel cycle) are poorly understood because polar-orbiting satellites (e.g., Landsat Series, Sentinel, Terra, Aqua) only provide one or two observations over each repeat cycle (e.g., 16 days) with constant overpass time for the same area. Geostationary satellites provide high-frequency land surface temperature (LST) observations throughout the day and the night, and thereby offer unprecedented opportunities for exploring the diurnal cycles of SUHI. Here we examined how the SUHI intensity varied over the course of the diurnal cycle in the Boston Metropolitan Area using LST observations from the NOAA's latest generation of Geostationary Operational Environmental Satellites (GOES-R). GOES-R LST was strongly correlated with MODIS LST (R2 = 0.98, p < 0.0001) across urban core, suburban, and rural areas. We calculated the SUHI intensity at an hourly time step for both the urban core and suburban areas using GOES-R LST data. The maximum SUHI intensity for the urban core occurred near noon, and was +3.0 °C (12:00), +5.4 °C (12:00), +4.9 °C (11:00), and +3.7 °C (12:00) in winter, spring, summer, and autumn, respectively. The maximum intensity for the suburban area was about 3.0 °C lower in spring and summer and 2.0 °C lower in autumn and winter than that of the urban-core area. The minimum SUHI intensity occurred at nighttime, and ranged from -1.0 °C to +1.0 °C. The difference in the nighttime SUHI intensity between urban core and suburban area was insignificant for all seasons except the summer. The SUHI intensity showed similar diurnal variations across the seasons. Throughout the year, the maximum SUHI intensity (+2.7-+5.8 °C) at the urban core occurred at 11:00-14:00 (local time), while the minimum SUHI intensity (-0.6-+0.9 °C) was commonly observed at 00:00-07:00 and 17:00-23:00. We also found different relationships between SUHI intensity and potential drivers within a diurnal cycle, characterized by the strongest correlation with impervious surface area and population size during the middle of the day, and with tree canopy cover at night. Our research highlights the great potential of the new-generation geostationary satellites in revealing the detailed diurnal variations of SUHI. Our findings have implications for informing urban planning and public health risk management.

7.
J Orthop Sci ; 26(4): 636-643, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32798112

RESUMO

BACKGROUND: Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting (PR + CSC) for treatment of displaced and intra-articular calcaneal fractures (DIACFs) is a difficult technique, because the minimally invasive treatment has limited exposure and cannot be used to reduce articular surface under direct vision. The goal of this study was to apply 3D printing technology to preoperative planning and surgery of DIACFs, and to evaluate its effectiveness, feasibility and safety in fracture repair. METHODS: We enrolled 81 patients with DIACFs in the study from August 2015 to August 2017. Patients with DIACFs in our hospital were randomly divided into the 3D printing group (40 cases) and the conventional group (41 cases). The operation duration, blood loss volume and the number of fluoroscopy were compared. Radiological results were evaluated using radiographs and functional results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score. The complications were also assessed. In addition, we made a questionnaire to verify the usefulness of the 3D printed model for both doctors and patients. RESULTS: The operation duration, blood loss volume and the number of fluoroscopy in 3D printing group were significantly less than that in the conventional group. Besides, 3D printing group achieved significantly better radiological results than conventional group both postoperatively and at the final follow-up except the calcaneal width at the final follow-up. The AOFAS score in the 3D printing group was significantly higher than that in the conventional group. In addition, the questionnaire from doctors and patients exhibited high scores of overall satisfaction of the 3D printed models. As for complications, there was no significant difference among the two groups. CONCLUSION: This study suggested the clinical feasibility of PR + CSC assisted by 3D printing technology in the treatment of DIACFs. LEVEL OF EVIDENCE: II.


Assuntos
Calcâneo , Fraturas Ósseas , Fraturas Intra-Articulares , Parafusos Ósseos , Calcâneo/diagnóstico por imagem , Calcâneo/cirurgia , Sulfato de Cálcio , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Humanos , Fraturas Intra-Articulares/diagnóstico por imagem , Fraturas Intra-Articulares/cirurgia , Impressão Tridimensional , Resultado do Tratamento
8.
J Foot Ankle Surg ; 59(6): 1209-1214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32950372

RESUMO

Flexible flatfoot is a common deformity in the pediatric population and can cause a range of symptoms and reduce the quality of life. Subtalararthroereisis may be appropriate for pediatric population whose conservative management had failed to relief their symptoms typically for at least 6 months. Subtalararthroereisis has been developed for a long time, but the use of interference screw for the treatment of pediatric flexible flatfoot has not been reported. From January, 2016 to June, 2017, we operated on 21 children (39 feet) between the ages of 8 and 14 years. The clinical assessment was based on the American Orthopedic Foot and Ankle Society (AOFAS) hind-foot scale and the Chippaux-Smirak Index (CSI) measurements. And the anatomical parameters assessment was based on the radiographs and photographs. The postoperative AOFAS scores and CSI measurements were improved compared with preoperative AOFAS scores and CSI measurements. Postoperative anatomical parameters achieved significantly better results than preoperative anatomical parameters. In conclusion, the use of interference screw in subtalararthroereisis for the treatment of pediatric flexible flatfoot deformity is an effective, simple and minimally invasive solution.


Assuntos
Pé Chato , Adolescente , Parafusos Ósseos , Criança , Pé Chato/diagnóstico por imagem , Pé Chato/cirurgia , Humanos , Osteotomia , Qualidade de Vida , Radiografia , Resultado do Tratamento
9.
Am J Pathol ; 190(12): 2376-2386, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32926854

RESUMO

Because chondrocytes are the only resident cells in articular cartilage, the steady state of these cells is important for the maintenance of joint function. In various osteoarthritis diseases, chondrocytes undergo a series of pathophysiologic changes, leading to the loss of chondrocytes and the degradation of extracellular matrix (ECM). This study found that Cytoplasmic localized histone deacetylase 6 (HDAC6) is up-regulated on the articular surface in a destabilization of the medial meniscus-induced mouse osteoarthritis model. Because HDAC6 is highly related to the acetylation of tubulin and the function of the microtubule system is closely related to material transport and signal transduction, the relationship between the expression level or activity of HDAC6 and the fate of chondrocytes in vitro and in vivo were confirmed. Primary chondrocytes overexpressing DNA-HDAC6 with plasmid were constructed in vitro, and HDAC6 inhibitor Tubastatin A was selected to inhibit HDAC6 enzyme activity in vivo and in vitro. Subsequently, mitochondrial spatial arrangement, degradation of ECM, and pathological changes in joint were defined. The results indicate that overexpression of HDAC6 causes mitochondrial dysfunction and promotes reactive oxygen species production, leading to degradation of ECM. Tubastatin A treatment after osteoarthritis ameliorates the degradation of cartilage and improves the microenvironment and function of the joint. HDAC6 may be targeted to treat osteoarthritis.


Assuntos
Desacetilase 6 de Histona/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Microtúbulos/efeitos dos fármacos , Osteoartrite/tratamento farmacológico , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Animais , Histona Desacetilases/efeitos dos fármacos , Histona Desacetilases/metabolismo , Humanos , Camundongos , Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Osteoartrite/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
In Vitro Cell Dev Biol Anim ; 56(1): 42-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31907757

RESUMO

LncRNA TUG1 has the potential to promote the osteogenic differentiation of several cells, but the role of lncRNA TUG1 in osteogenic differentiation of tendon stem/progenitor cells (TSPCs) is still unknown. This study aims to determine the role of lncRNA TUG1 in osteogenic differentiation of TSPCs. bFGF, RUNX2, and Osterix protein expressions were detected by western blot. LncRNA TUG1 and bFGF expression was detected by qRT-PCR. RNA immunoprecipitation (RIP) assay was used to confirm the interaction between TUG1 and bFGF2. Ubiquitination assay was used to determine the ubiquitination of bFGF protein. During osteogenic differentiation, the protein expression of bFGF was significantly downregulated in TSPCs, and the expression of TUG1 was significantly elevated in TSPCs. Interfering TUG1 or overexpressing bFGF suppressed osteogenic differentiation of TSPCs. In addition, lncRNA TUG1 interacted with bFGF, and lncRNA TUG1 promoted the ubiquitination of bFGF protein. We also determined that lncRNA TUG1 downregulated bFGF protein expression through promoting the ubiquitination of bFGF. LncRNA TUG1 promoted the osteogenic differentiation of TSPCs through promoting bFGF ubiquitination.


Assuntos
Diferenciação Celular/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Osteogênese/genética , RNA Longo não Codificante/metabolismo , Ubiquitinação , Animais , Camundongos Endogâmicos C57BL , Proteólise , RNA Longo não Codificante/genética , Células-Tronco/metabolismo , Tendões/citologia
11.
Orthop Surg ; 12(1): 124-132, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31849195

RESUMO

OBJECTIVE: To assess the long-term outcomes after percutaneous reduction (PR) and screw fixation versus plate fixation via the sinus tarsi approach (STA) for displaced intra-articular calcaneal fractures (DIACF). METHODS: This retrospective study included a total of 150 patients (June 2008-August 2011), comprising 85 men and 65 women (mean age, 38.4 years), who were assigned to the PR group or the STA group. The inclusion criteria were DIACF (>2 mm) including Sanders type II and III, closed fracture, unilateral fracture, no history of smoking or no smoking during hospitalization and 3 months after surgery, and follow-up time not less than 8 years. The exclusion criteria were clear surgical contraindications (severe cardiovascular and cerebrovascular diseases), local or systemic infection symptoms, diagnosis with diabetes or lower extremity vascular disease, and Sanders type IV or open fractures. Outcomes were assessed by means of the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot scores, radiographic images, and postoperative complications. RESULTS: The mean follow-up period was 8.7 years (range, 8.0-10.0 years). The AOFAS scores in the PR group during the follow-up period were 54.2 ± 5.1, 85.8 ± 4.0, 88.1 ± 3.8, 87.9 ± 3.6, 87.8 ± 3.9, 86.9 ± 3.9, respectively, and in the STA group were 55.0 ± 5.6, 84.5 ± 5.2, 87.1 ± 3.8, 86.9 ± 3.8, 87.7 ± 3.3, and 87.6 ± 2.8, respectively. There was no significant difference in AOFAS scores, Bohler's angle, Gissane's angle, calcaneal length, and height between the two groups (P > 0.05). The good to excellent rate of the PR group (80.8%) was less than that of the STA group (91.7%) (P = 0.055). For Sanders III fractures, the good to excellent rate of the PR group (33.3%) was less than that of the STA group (76.9%) (P = 0.029). For calcaneal width recovery, the STA group performed better than the PR group (P < 0.05). The incidence of postoperative complications in the PR group (12.8%) was lower than that in the STA group (27.8%) (P = 0.026), of which the incidence of wound complications was 3.8% in the PR group and 13.9% in the STA group (P = 0.041). In addition, there was no significant difference in other postoperative complications such as sural nerve injury, peroneus longus and brevis muscle injury, calcaneal valgus symptoms, lateral impingement symptoms, and subtalar arthritis (P > 0.05). CONCLUSION: From the 8-10-year follow-up results of PR and STA as surgical procedures for the treatment of DIACF, it was found that there was no significant difference in the overall efficacy between them. STA was found to be superior to the PR in terms of the recovery of calcaneal width, providing more stable fixation for Sanders III fractures. PR was found to be more effective in reducing wound complications.


Assuntos
Placas Ósseas , Parafusos Ósseos , Calcâneo/cirurgia , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Adulto , Calcâneo/lesões , Feminino , Seguimentos , Fixação Interna de Fraturas/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
12.
J Foot Ankle Surg ; 59(3): 522-528, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31864842

RESUMO

Many lateral malleolus fractures have been found to have syndesmosis injuries after anatomic reduction. The main methods for the treatment of syndesmosis injuries are screw fixation and suture-button flexible fixations. In pursuit of innovation, we have designed a novel syndesmotic plate (NSP) for simultaneous fixation of lateral malleolus fractures and distal tibiofibular syndesmosis injuries. The purpose of this study is to compare the biomechanical characteristics of the NSP to syndesmotic screw and suture-button fixations. Twelve adult cadaveric specimens were used in this experiment. Axial loading as well as rotation torque were applied in 3 different ankle positions: neutral, dorsiflexion, and plantarflexion. After the initial specimens were tested, they were made into a pronation-abduction III fracture model as described by Lauge-Hansen. Subsequently, the specimens were fixed sequentially using a distal fibular anatomic locking plate (DFALP) combined with syndesmotic screws, DFALP combined with suture button, and NSP. Then the above tests were repeated. The syndesmotic displacement and the strain of the tibia and fibula were recorded during the experiment. In most cases, the displacements and strains of the NSP group and the screw group were smaller than the suture button groups and the native (SBGAN) (p < .05), and the displacements and strains of the NSP group were also slightly smaller than the screw group in most cases, and there was no significant difference between the 2 groups. The NSP we developed has a fixed strength no less than the traditional syndesmotic screw fixation. This provides us a new idea for the treatment of distal tibiofibular syndesmosis injuries.


Assuntos
Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/cirurgia , Placas Ósseas , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Âncoras de Sutura , Adulto , Fraturas do Tornozelo/fisiopatologia , Traumatismos do Tornozelo/fisiopatologia , Cadáver , Feminino , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Amplitude de Movimento Articular , Técnicas de Sutura , Suporte de Carga
13.
Sci Total Environ ; 684: 567-577, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31158620

RESUMO

Excessive urban growth has led to an urban environmental degradation in megacities in less developed countries. Using fine particulate matter (PM2.5) concentration, land surface temperature (LST), and normalized difference vegetation index (NDVI) data obtained by satellite remote sensing, we analysed the inter-annual variations and trends in the urban environment of 17 megacities in Eurasia from 2000 to 2016. Taking the average environmental condition for all the megacities in 2000 as the baseline, the urban environmental conditions were evaluated by a Comprehensive Environmental Index (CEI) from 2001 to 2016. The variation and trends analysis of CEI revealed that the overall environmental conditions in Chennai, Dhaka, Kolkata and Tianjin showed significant deterioration trends. Environmental qualities in newly developed urban areas experienced degradation in Bangalore, Beijing, and Mumbai. The area of environmentally deteriorated urban land has been expanding in Bangalore, Chennai, Delhi, Kolkata, and Mumbai in India and Dhaka in Bangladesh since 2001. By contrast, the area of environmentally degraded urban land in Chinese megacities expanded to the largest extent in the period of 2007-2009 and decreased afterwards. The result suggests that greening and strong emission control strategies significantly contributed to urban environmental quality enhancement in rapidly developing megacities.

14.
Sci Total Environ ; 666: 274-284, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30798237

RESUMO

Previous studies of urbanization have largely focused on the irreversible urban growth process and the conversion of non-urban lands into impervious surfaces, but less on the conversion from impervious surfaces to green space, also referred to as deurbanization. However, urbanization and deurbanization are both typical urban renewal process, which may happen simultaneously during the urban renewal. In this study, we proposed a new method to retrieve and map annual impervious surface percentage (ISP) and to characterize urban growth patterns using time series medium- resolution images. The method is implemented by employing the Cubist tree model for annual ISP inversion (AoCubist), optimizing multi-temporal Landsat composite images to minimize the impact of phenology and inter-year climate variation, and developing the C5.0 decision tree algorithm with temporal-spatial filtering rules to improve the space-time continuity and separability of patterns derived by unsupervised K-means classification. The method was applied to investigate the urban renewal in Guangzhou, China, between 2000 and 2010. The results demonstrate that the use of ISP slope series can capture the spatial variations and temporal trends of urban growth. Validation by fieldwork and comparing with Google Earth imagery indicates that our classification yielded a reasonable overall accuracy, ranging from 88.32% to 90.85%. Annual urban expansion rate remained between 4% and 10%, while annual deurbanization rate varied from 1% to 5%. In addition, the total pixels of rapid deurbanization surpassed that of rapid urban expansion. This finding suggests that various change directions occurred in the urban renewal process and that deurbanization was a way to counter-balance the rapid urbanization. This study provides a solid methodology for ISP change detection and fresh insight into the characteristics of urban growth in terms of timing, duration, and magnitude.

15.
Sci Total Environ ; 650(Pt 1): 515-529, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30205342

RESUMO

Normalization of land surface temperature (LST) relative to environmental factors is of great importance in many scientific studies and applications. The purpose of this study was to develop physical models based on energy balance equations for normalization of satellite derived LST relative to environmental parameters. For this purpose, a set of remote sensing imagery, meteorological and climatic data recorded in synoptic stations, and soil temperatures measured by data loggers were used. For modeling and normalization of LST, a dual-source energy balance model (dual-EB), taking into account two fractions of vegetation and soil, and a triple -source energy balance model (triple-EB), taking into account three fractions of vegetation, soil and built-up land, were proposed with either regional or local optimization strategies. To evaluate and compare the accuracy of different modeling results, correlation coefficients and root mean square difference (RMSE) were computed between modeled LST and LST obtained from satellite imagery, as well as between modeled LST and soil temperature measured by data loggers. Further, the variance of normalized LST values was calculated and analyzed. The results suggested that the use of local optimization strategy increased the accuracy of the normalization of LST, compared to the regional optimization strategy. In addition, no matter the regional or local optimization strategy was employed, the triple-EB model out-performed consistently the dual-EB model for LST normalization. The results show the efficiency of the local triple-EB model to normalize LST relative to environmental parameters. The correlation coefficients were close to zero between all of the environmental parameters and the normalized LST. In other words, normalized LST was completely independent of the environmental parameters considered by this research.

16.
Sensors (Basel) ; 18(11)2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30463390

RESUMO

There is limited research in land surface temperatures (LST) simulation using image fusion techniques, especially studies addressing the downscaling effect of LST image fusion. LST simulation and associated downscaling effect can potentially benefit the thermal studies requiring both high spatial and temporal resolutions. This study simulated LSTs based on observed Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) LST imagery with Spatial and Temporal Adaptive Reflectance Fusion Model, and investigated the downscaling effect of LST image fusion at 15, 30, 60, 90, 120, 250, 500, and 1000 m spatial resolutions. The study area partially covered the City of Los Angeles, California, USA, and surrounding areas. The reference images (observed ASTER and MODIS LST imagery) were acquired on 04/03/2007 and 07/01/2007, with simulated LSTs produced for 4/28/2007. Three image resampling methods (Cubic Convolution, Bilinear Interpolation, and Nearest Neighbor) were used during the downscaling and upscaling processes, and the resulting LST simulations were compared. Results indicated that the observed ASTER LST and simulated ASTER LST images (date 04/28/2007, spatial resolution 90 m) had high agreement in terms of spatial variations and basic statistics based on a comparison between the observed and simulated ASTER LST maps. Urban developed lands possessed higher LSTs with lighter tones and mountainous areas showed dark tones with lower LSTs. The Cubic Convolution and Bilinear Interpolation resampling methods yielded better results over Nearest Neighbor resampling method across the scales from 15 to 1000 m. The simulated LSTs with image fusion can be used as valuable inputs in heat related studies that require frequent LST measurements with fine spatial resolutions, e.g., seasonal movements of urban heat islands, monthly energy budget assessment, and temperature-driven epidemiology. The observation of scale-independency of the proposed image fusion method can facilitate with image selections of LST studies at various locations.

17.
Injury ; 49(6): 1228-1232, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29731123

RESUMO

OBJECTIVE: To discuss the effect and advantage of the improved oval forceps suture-guiding method combined with anchor nail in the treatment of acute Achilles tendon rupture. METHODS: A retrospective research was performed on 35 cases of acute Achilles tendon rupture treated with the improved oval forceps suture-guiding method from January 2013 to October 2016. Instead of the Achillon device, we perform the Achillon technique with the use of simple oval forceps, combined with absorbable anchor nail, percutaneously to repair the acute Achilles tendon rupture. RESULTS: All patients were followed up for at least 12 months (range, 12-19 months), and all the patients underwent successful repair of their acute Achilles tendon rupture using the improved oval forceps suture-guiding method without any major intra- or postoperative complications. All the patients returned to work with pre-injury levels of activity at a mean of 12.51 ±â€¯0.76 weeks. Mean AOFAS ankle-hindfoot scores improved from 63.95 (range, 51-78) preoperatively to 98.59 (range, 91-100) at last follow-up. This was statistically significant difference (P < 0.001). Mean Achilles Tendon Total Rupture Score (ATRS) at final follow-up was 94.87 (range, 90-100). CONCLUSION: The improved oval forceps suture-guiding method could make the advantage of minimally invasive repair with less complications, reduced surgical time and similar functional outcomes compared with the traditional open surgery. In addition, our new technique could save the cost of surgery with the compare of the Achillon device. At the same time for the cases which the remote broken tendon ends were within 2 cm from the calcaneal nodules, because of the less tendon tissue was left in the remote side, traditional percutaneous methods are incapable to ensure the reconstruction strength. By using the anchor nail, the improved technique has better repair capacity and expands the operation indication of oval forceps method.


Assuntos
Tendão do Calcâneo/lesões , Articulação do Tornozelo/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Ruptura/cirurgia , Técnicas de Sutura , Tendão do Calcâneo/cirurgia , Adulto , Articulação do Tornozelo/fisiopatologia , Análise Custo-Benefício , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Estudos Retrospectivos , Instrumentos Cirúrgicos , Técnicas de Sutura/instrumentação , Resultado do Tratamento , Cicatrização
18.
J Environ Manage ; 206: 1274-1286, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28743563

RESUMO

Anthropogenic heat flux (Qf), which originates through energy consumption from buildings, industrial plants, vehicle exhausts, and human metabolism releases, is an important component in the urban Surface Energy Balance (SEB) system, and is key to understanding of many urban environmental issues. The present study provided a hybrid Qf modeling approach, which combined the inventory and GIS approach to create a 365-day hourly Qf profile at 120 m spatial resolution in Los Angeles County, California, USA. Qf was estimated by separate calculation of heat release from buildings, traffics, and human metabolism, respectively. The results indicated that Qf showed different magnitudes and diurnal patterns between workdays (dual-peak shape) and weekends/holidays, and also varied with seasons, and land use types. Qf yielded the highest values in the summer workdays, with its maximum value of 7.76 w/m2. Qf in hot summer workdays was obviously higher than that in the average summer workdays, which caused by higher demands for space cooling in buildings, and can reach 8.14 w/m2 at maximum. Building energy consumption was identified as the dominant contributor to the Qf in Downtown Los Angeles, which was found to have the largest mean Qf throughout the year among all neighborhoods. It can be concluded that Qf in the downtown was more significant in workdays than that in non-workdays, and its maximum value can reach 100 w/m2. It is suggested that our approach may have wider applicability for Qf estimation in large areas compared with the existing studies, as all the data used were available to the public. A high spatial and temporal Qf profile, which can readily be incorporated into urban energy balance and Urban Heat Island (UHI) studies, provides valuable data and information for pertinent government agencies and researchers.


Assuntos
Temperatura Alta , Emissões de Veículos , Monitoramento Ambiental , Humanos , Los Angeles
19.
Sci Total Environ ; 409(20): 4235-41, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21802710

RESUMO

Previous studies have analyzed the number and location of bird infections with human incidence of West Nile virus (WNV) as well as the effects of environmental and socioeconomic factors on WNV propagation. However, such associations require more quantitative analyses. This study is intended to quantitatively analyze the relationship in eight counties/independent cities in the northern Virginia, based on an integrated analysis of spatially explicit information on precipitation, land cover, infrastructure, and demographic data using Geographical Information Systems, remote sensing, and statistics. Results show that bird infections in years 2002-2003 were closely associated with low to medium level of impervious surface with certain percentage of canopy and precipitation. Environmental and socioeconomic factors such as percentages of impervious surface, canopy, senior population (65 and older), old houses, bird risk areas, and low-income population were important indicators of human WNV risk in 2002. Limited impervious surface with some canopy provides suitable habitats for WNV transmission, where bird-feeding mosquitoes can forage for blood meals from nesting/roosting birds. Certain socioeconomic conditions such as old houses were linked with human infections by providing favorable environmental conditions, i.e., mature trees with abundant canopy and settled storm sewer systems. It should be noted that the current results may be biased toward urban environments, where dead birds were more likely found, and because the sampling efforts for the bird mortality were rather based on local residents' reports than a designed random sampling method. This geospatial study contributes toward better targeting of WNV prevention within the study area. It also provides an example of how geospatial methods and variables may be used in understanding the ecology of human WNV risk for other areas.


Assuntos
Doenças das Aves/epidemiologia , Surtos de Doenças , Sistemas de Informação Geográfica , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental , Migração Animal , Animais , Doenças das Aves/transmissão , Doenças das Aves/virologia , Aves , Análise Discriminante , Reservatórios de Doenças/virologia , Humanos , Incidência , Urbanização , Virginia/epidemiologia , Febre do Nilo Ocidental/transmissão , Febre do Nilo Ocidental/veterinária , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/isolamento & purificação
20.
Sci Total Environ ; 409(20): 4387-405, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21835439

RESUMO

Modeling the effects of past and current land use composition and climatic patterns on surface water quality provides valuable information for environmental and land planning. This study predicts the future impacts of urban land use and climate changes on surface water quality within Des Plaines River watershed, Illinois, between 2010 and 2030. Land Change Modeler (LCM) was used to characterize three future land use/planning scenarios. Each scenario encourages low density residential growth, normal urban growth, and commercial growth, respectively. Future climate patterns examined include the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenario (SRES) B1 and A1B groups. The Soil and Water Assessment Tool (SWAT) was employed to estimate total suspended solids and phosphorus concentration generated at a 10 year interval. The predicted results indicate that for a large portion of the watershed, the concentration of total suspended solids (TSS) would be higher under B1 and A1B climate scenarios during late winter and early spring compared to the same period in 2010; while the summer period largely demonstrates a reverse trend. Model results further suggest that by 2020, phosphorus concentration would be higher during the summer under B1 climate scenario compared to 2010, and is expected to wane by 2030. The projected phosphorus concentrations during the late winter and early spring periods vary across climate and land use scenarios. The analysis also denotes that middle and high density residential development can reduce excess TSS concentration, while the establishment of dense commercial and industrial development might help ameliorate high phosphorus levels. The combined land use and climate change analysis revealed land use development schemes that can be adopted to mitigate potential future water quality impairment. This research provides important insights into possible adverse consequences on surface water quality and resources under certain climate change and land use scenarios.


Assuntos
Mudança Climática , Simulação por Computador , Rios/química , Urbanização/tendências , Poluentes Químicos da Água/análise , Abastecimento de Água/normas , Chicago
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...