Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
World J Surg Oncol ; 22(1): 120, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702816

RESUMO

BACKGROUND: REBOA is a method used to manage bleeding during surgery involving sacropelvic tumors. Nevertheless, studies on the use of REBOA among elderly people are lacking. The aim of this research was to investigate the efficacy and safety of Zone III REBOA in patients aged more than 70 years. METHODS: A comparative study was conducted using case-control methods. A group of patients, referred to as Group A, who were younger than 70 years was identified and paired with a comparable group of patients, known as Group B, who were older than 70 years. Continuous monitoring of physiological parameters was conducted, and blood samples were collected at consistent intervals. RESULTS: Totally, 188 participants were enrolled and received REBOA. Among the 188 patients, seventeen were aged more than 70 years. By implementing REBOA, the average amount of blood loss was only 1427 ml. Experiments were also conducted to compare Group A and Group B. No notable differences were observed in terms of demographic variables, systolic blood pressure (SBP), arterial pH, lactate levels, blood creatinine levels, potassium levels, or calcium levels at baseline. Additionally, after the deflation of the REBOA, laboratory test results, which included arterial pH, lactate, potassium concentration, calcium concentration, and blood creatinine concentration, were not significantly different (P > 0.05). CONCLUSION: This study indicated that in selected patients aged more than 70 years can achieve satisfactory hemodynamic and metabolic stability with Zone III REBOA. LEVEL OF EVIDENCE: Therapeutic study, Level III.


Assuntos
Neoplasias Pélvicas , Humanos , Feminino , Masculino , Idoso , Estudos de Casos e Controles , Pessoa de Meia-Idade , Neoplasias Pélvicas/cirurgia , Neoplasias Pélvicas/patologia , Seguimentos , Prognóstico , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Perda Sanguínea Cirúrgica/prevenção & controle , Idoso de 80 Anos ou mais , Adulto
2.
Inorg Chem ; 62(1): 238-246, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36528812

RESUMO

Hofmann metal-organic frameworks (MOFs) are a variety of hybrid inorganic-organic polymers with a stable framework, plentiful adjustable pore size, and redox active sites, which display great application potential in energy storage. Unfortunately, the rapid and uncontrollable rate of coordination reaction results in a large size and an anomalous morphology, and the low electrical conductivity also severely limited further development, so there are few literature studies on Hofmann MOFs as anode materials for rechargeable batteries. Introducing graphene oxide can not only greatly facilitate the formation of a continuous conductive network but also effectively anchor and disperse MOF particles by utilizing the two-dimensional planar structure, thus reducing the sizes and agglomeration of particles. In this work, various mass ratios of graphene oxide with 3D Hofmann Ni-Pz-Ni MOFs were prepared via a simple one-pot solvothermal method. Benefiting from the gradually increasing capacitance characteristic during the continuous charge/discharge process, the Ni-Pz-Ni/GO-20% electrode exhibits a great reversible capacity of 896.1 mAh g-1 after 100 cycles and excellent rate capability, which will lay a theoretical foundation for exploring the high-performance Hofmann MOFs in the future.

3.
BMC Musculoskelet Disord ; 22(1): 549, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34134687

RESUMO

BACKGROUND AND OBJECTIVES: Treatment of benign osteolytic lesions in the femoral head and neck can be extremely challenging, particularly in children with open physis or for aggressive tumors with pathological fracture. There remains the difficult management decision as to whether to perform complete excision of the involved area or only curettage. Moreover, there is no agreed consensus on the optimal approach to lesion access when performing curettage, which included the transcervical, open and direct approach. The current systematic review aims to provide guidance for selection of surgical methods in clinical practice by comparing the advantages and drawbacks of different procedures. METHODS: A comprehensive literature search of PubMed, Embase and Web of Science databases were executed for human studies restricted to the English language. The search was filtered to include studies published from January 1980 to January 2020. RESULTS: A total of 33 articles including 274 patients were enrolled in the final analysis. The most common diagnosis was chondroblastoma (CBT) (104, 38.0%), followed by giant cell tumor (GCT) (56, 20.4%). There were 57 (20.8%) patients with pathological fracture. Intralesional curettage was performed in 257 (93.8%) patients with the local recurrence of 12.5% at the mean follow-up of 51.5 months. The patients who were presented with open physis or curetted via transcervical approach developed higher local recurrence in patients with CBT (P < 0.001). The local recurrence rate of GCT is 33.3% after curettage, while 8 of 9 (88.9%) patients with fracture were treated successfully with joint preservation. Two of 45 (4.4%) patients developed avascular necrosis (AVN) of femoral head after surgical hip dislocation. The reported Musculoskeletal Tumor Society (MSTS) Score was comparable among patients with different approaches to curettage. CONCLUSION: The majority of benign osteolytic lesions in the femoral head and neck can be treated with intralesional curettage with acceptable local tumor control and satisfactory function. The incidence of local recurrence might be decreased dramatically for lesion access under direct visualization. The native joint maintenance could be achieved even in patients with aggressive lesions presenting pathological fracture.


Assuntos
Neoplasias Ósseas , Cabeça do Fêmur , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/cirurgia , Criança , Curetagem , Fêmur , Humanos , Recidiva Local de Neoplasia , Estudos Retrospectivos , Resultado do Tratamento
4.
Clin Orthop Relat Res ; 476(3): 490-498, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29529630

RESUMO

BACKGROUND: Although aortic balloon occlusion has been shown to reduce blood loss during sacral tumor resections, it has not been validated in larger sacral tumors involving the lower lumbar spine. If such an approach were shown to be associated with less blood loss, it might aid the tumor surgeon in resecting these difficult tumors. QUESTIONS/PURPOSES: (1) Is the use of aortic balloon occlusion associated with reduced blood loss in sacral tumor resections when the lower lumbar spine is also involved? (2) Does the use of the aortic balloon prolong total operating time? (3) What complications are associated with the use of a balloon? METHODS: We retrospectively studied all 56 patients diagnosed with sacral tumors involving the lower lumbar spine (L4, L5) who were treated surgically between 2004 and 2015 at our institute. During that time, 30 of the patients received aortic balloon occlusion therapy, whereas 26 of the patients did not. We generally used aortic balloon occlusion during procedures for hypervascular lesions (for example, giant cell tumors or metastatic renal cancers), primary malignant lesions, and recurrent lesions. We generally avoided use of aortic balloon occlusion in patients with anatomic defects of the aorta (aortic dissection or aneurysm was strictly contraindicated), renal artery bifurcation caudal to the L2 to L3 disc, age older than 70 years or younger than 12 years, history of Stage 2 hypertension [], history of balloon use in previous surgeries, and presence of unstable plaque on abdominal CT. The demographic data, intraoperative blood loss, transfusion volume, operating time, and postoperative wound drainage between the two groups were collected and analyzed. Balloon-related complications were identified. Followup in terms of balloon-related complications was conducted in all 56 patients for at least 6 months after surgery. RESULTS: Intraoperative blood loss was determined to be less in patients treated with the balloon compared with those treated without the balloon (median volume, 2000 mL, range, 400-6000 mL versus 2650 mL, range, 550-6800 mL, respectively; median difference, 605 mL; 95% confidence interval [CI], 100-1500 mL; p = 0.035). Total operative time was not prolonged in the balloon group (including balloon insertion time) compared with those treated without it (median time, 215 minutes, range, 110-430 minutes versus 225 minutes, range, 115-340 minutes, respectively; median difference, 10 minutes; 95% CI, -40 to 30 minutes; p = 0.902). Balloon-related vascular complications included local hematoma at the puncture site in five patients, femoral artery spasm in three patients, lower limb ischemia in one patient, and femoral artery pseudoaneurysm in one patient. Acute kidney injury was found in two patients in the balloon group. CONCLUSIONS: This study demonstrated that placement of the aortic balloon at a level just caudal to the renal artery bifurcation was associated with lower intraoperative blood loss and transfusion in lumbosacral tumor resections. However, procedure-specific complications were common and there was no benefit to total operative time. We suggest that the surgical procedures still need to be further refined to minimize complications. We also recommend that prospective studies be undertaken to confirm the efficacy of aortic balloon occlusion in surgery for lumbosacral tumors. LEVEL OF EVIDENCE: Level III, therapeutic study.


Assuntos
Aorta , Oclusão com Balão , Perda Sanguínea Cirúrgica/prevenção & controle , Vértebras Lombares/cirurgia , Procedimentos Ortopédicos , Sacro/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Idoso , Aorta/diagnóstico por imagem , Aorta/fisiopatologia , Aortografia , Oclusão com Balão/efeitos adversos , Feminino , Humanos , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Procedimentos Ortopédicos/efeitos adversos , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Fatores de Risco , Sacro/patologia , Neoplasias da Coluna Vertebral/patologia , Fatores de Tempo , Resultado do Tratamento
5.
Eur Spine J ; 24(10): 2201-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26187620

RESUMO

PURPOSE: To determine the frequency of major complications and identify related risk factors in surgery for hypervascular spinal tumors after preoperative selective arterial embolization. METHODS: Patients with spinal tumors who underwent preoperative embolizations between January 2010 and March 2013 were retrospectively reviewed. Perioperative complications were classified as either major or minor. Preoperative and intraoperative factors were analyzed for any association with major complications using univariate and multivariate regression analysis. RESULTS: There were 120 embolizations with subsequent 120 spine operations that met the inclusion and exclusion criteria. Overall, 27.5% (33/120) experienced major complications and 11.7% (14/120) had at least two major complications. Respiratory complications were the most commonly seen with a rate of 10.8% (13/120). Multivariate regression analysis identified two risk factors for major complications: reoperation and higher score of surgical invasiveness index. Two risk factors were identified for two or more major complications: age≥65 years and higher score of surgical invasiveness index. Two risk factors were identified for major respiratory complications: thoracic surgery and higher score of surgical invasiveness index. However, embolization-related factors did not reach significance in the multiple regression model. CONCLUSION: Major complications in surgery for hypervascular spinal tumors after embolization are prevalent. Risk factors identified in this study are useful prognostic indicators when considering surgical treatment combined with embolization.


Assuntos
Procedimentos Neurocirúrgicos/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Neoplasias da Coluna Vertebral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Embolização Terapêutica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/irrigação sanguínea , Neoplasias da Coluna Vertebral/epidemiologia , Neoplasias da Coluna Vertebral/patologia , Neoplasias da Coluna Vertebral/terapia , Adulto Jovem
6.
World J Surg Oncol ; 13: 282, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-26399398

RESUMO

BACKGROUND: The reconstruction of an intercalary bone defect after a tumor resection of a long bone remains a challenge to orthopedic surgeons. Though several methods have been adopted to enhance the union of long segmental allografts or retrieved segmental autografts to the host bones, still more progresses are required to achieve a better union rate. Several methods have been adopted to devitalize tumor bone for recycling usage, and the results varied. We describe our experiences of using devitalized tumor-bearing bones for the repairing of segmental defects after tumor resection. METHODS: Twenty-seven eligible patients treated from February 2004 to May 2012 were included. The segmental tumor bone (mean length, 14 cm) was resected, and then devitalized in 20% sterile saline at 65 °C for 30 min after the tumor tissue was removed. The devitalized bone was implanted back into the defect by using nails or plates. RESULTS: Complete healing of 50 osteotomy ends was achieved at a median time of 11 months (interquartile range (IQR) 9-13 months). Major complications included bone nonunion in four bone junctions (7.4%), devitalized bone fracture in one patient (3.7%), deep infection in three patients (11.1%), and fixation failure in two patients (7.4%). The bone union rates at 1 and 2 years were 74.1 and 92.6%, respectively. The average functional score according to the Musculoskeletal Tumor Society (MSTS) 93 scoring system was 93 % (IQR 80-96.7%). CONCLUSIONS: Incubation in 20% sterile saline at 65 °C for 30 min is an effective method of devitalization of tumor-bearing bone. The retrieved bone graft may provide as a less expensive alternative for limb salvage. The structural bone and the preserved osteoinductivity of protein may improve bone union.


Assuntos
Neoplasias Ósseas/cirurgia , Fraturas Ósseas/cirurgia , Osteossarcoma/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Sarcoma de Ewing/cirurgia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/patologia , Criança , Feminino , Seguimentos , Fraturas Ósseas/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteossarcoma/patologia , Prognóstico , Sarcoma de Ewing/patologia , Adulto Jovem
7.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(1): 165-9, 2015 Feb 18.
Artigo em Zh | MEDLINE | ID: mdl-25686350

RESUMO

OBJECTIVE: To determine the prognostic factors of primary osteosarcoma in adults. METHODS: This is a review of 54 patients older than 40 years (24 men and 30 women) who were treated between 1998 and 2011 at the authors' institution. Demographic information and follow-up data were obtained and statistically analyzed. RESULTS: Tumors involved the limbs in 30 patients (55.5%) and axial skeleton in 17 patients (31.5%), and arose from soft tissue in 7 patients (13%). And 6 patients (11.1%) had synchronous metastasis. According to our review, tumors were treated surgically in 52 patients (96.3%). Local recurrence was documented in 14 patients (26.9%). Metastasis after diagnosis appeared in 21 patients (38.9%). In the 52 patients who received the surgical treatment, the 5 year disease-free survival and overall survival rates were 43.7% and 50.4%, respectively. CONCLUSION: Adult patients with primary osteosarcoma had a poor clinical outcome. Inadequate surgical margins, more tumors in the axial location due to high recurrence rates, metastatic disease at presentation, and large tumor volumes were associated with significantly lower survival rates. Aggressive multi-agent treatment regimens might improve survival.


Assuntos
Neoplasias Ósseas/cirurgia , Recidiva Local de Neoplasia , Osteossarcoma/cirurgia , Adulto , Neoplasias Ósseas/diagnóstico , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Osteossarcoma/diagnóstico , Prognóstico , Taxa de Sobrevida
8.
J Surg Res ; 187(1): 142-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24405612

RESUMO

BACKGROUND: Large extracompartmental limb soft-tissue sarcoma with juxta-articular bone involvement poses major challenges in disease management. Radical resection of sarcoma frequently requires concomitant bone resection and reconstruction. We describe the clinical outcomes of endoprosthetic reconstruction and the complications associated with this procedure. METHODS: Thirty patients with soft-tissue sarcomas with local juxta-articular bone involvement in an extremity underwent surgery at our center between May 2004 and October 2011, 20 for primary sarcomas and 10 for local recurrences. Clinical data from those patients were analyzed retrospectively. The bone affected included the proximal femur (10 cases), the distal femur (nine cases), the proximal humerus (eight cases), the proximal tibia (two cases), or the total femur (one case). Wide excision of the tumor and the bone tissue involved was performed on every patient, followed by reconstruction of the subsequent defect using tumor endoprosthesis. All patients underwent regular follow-up for an average of 25 (range, 3-84) mo. RESULTS: Three patients had poor wound healing. Implant fractures leading to additional revisions occurred in two cases. Local tumor recurrence developed in four patients. There were 15 patients with lung metastases, and 11 patients died of disseminated metastases. In the latest follow-up, 14 patients survived free of disease and five were alive with tumors. The mean Musculoskeletal Tumor Society functional analysis for proximal femur, distal femur, proximal tibia, proximal humerus, and total femur were 90%, 82%, 73%, 71%, and 60%, respectively. The 2- and 5- y survival rates were 61.6% and 30.0%, respectively. CONCLUSIONS: Endoprosthetic reconstruction could yield satisfactory results as a wide excision and limb salvage therapeutic strategy for patients with large extracompartmental soft-tissue sarcomas with juxta-articular bone involvement. Acceptable complications occurred in the present report.


Assuntos
Neoplasias Ósseas/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Próteses e Implantes , Sarcoma/cirurgia , Neoplasias de Tecidos Moles/cirurgia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/mortalidade , Feminino , Fêmur/cirurgia , Seguimentos , Humanos , Úmero/cirurgia , Salvamento de Membro/métodos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos , Sarcoma/mortalidade , Neoplasias de Tecidos Moles/mortalidade , Tíbia/cirurgia , Resultado do Tratamento , Adulto Jovem
9.
ScientificWorldJournal ; 2014: 579328, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24592175

RESUMO

Fracturing by ductile damage occurs quite naturally in metal forming processes, and ductile fracture of strain-softening alloy, here 42CrMo steel, cannot be evaluated through simple procedures such as tension testing. Under these circumstances, it is very significant and economical to find a way to evaluate the ductile fracture criteria (DFC) and identify the relationships between damage evolution and deformation conditions. Under the guidance of the Cockcroft-Latham fracture criteria, an innovative approach involving hot compression tests, numerical simulations, and mathematic computations provides mutual support to evaluate ductile damage cumulating process and DFC diagram along with deformation conditions, which has not been expounded by Cockcroft and Latham. The results show that the maximum damage value appears in the region of upsetting drum, while the minimal value appears in the middle region. Furthermore, DFC of 42CrMo steel at temperature range of 1123~1348 K and strain rate of 0.01~10 s(-1) are not constant but change in a range of 0.160~0.226; thus, they have been defined as varying ductile fracture criteria (VDFC) and characterized by a function of temperature and strain rate. In bulk forming operations, VDFC help technicians to choose suitable process parameters and avoid the occurrence of fracture.


Assuntos
Força Compressiva , Aço/química , Ligas de Cromo/química , Dureza , Temperatura Alta
10.
Orthop Surg ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39030807

RESUMO

OBJECTIVE: Multitargeted tyrosine kinase inhibitors (TKIs) have been approved as second-line therapy in refractory sarcoma, prolonging progression-free survival (PFS) but with short-lived duration of disease control. Fruquintinib is a TKI that specifically inhibits vascular endothelial growth factor receptor-1,2,3 with no metabolism by liver enzymes. In this retrospective study, we assessed the efficacy and safety of fruquintinib-based treatment in patients with refractory sarcoma after developing several lines of TKI resistance. METHODS: We retrospectively analyzed the clinical data of patients with refractory sarcoma after they had developed several lines of resistance to TKIs and who received fruquintinib-based treatment from November 2021 to August 2023. The primary endpoint was the progression-free survival rate at 4 months (4m-PFSR). Secondary endpoints were the median PFS, overall survival (OS), objective response rate, disease control rate, and adverse effects (AEs). PFS and OS were estimated using the Kaplan-Meier method. A log-rank test was used to compare survival curves between different clinical and pathological factors. Cox proportional hazards analysis was performed to identify PFS-related prognostic factors. RESULTS: We included 124 patients: 56 (45.2%) with osteosarcoma, 28 (22.6%) with Ewing sarcoma, seven (5.6%) with chondrosarcoma, and 33 (26.6%) with soft tissue sarcomas (STS). Only 18 (14.5%) patients received monotherapy with fruquintinib. With a median follow-up time of 6.8 (interquartile range [IQR], 4.6-9.4) months, 22 (17.7%) patients had partial response and 78 (62.9%) had stable disease. The 4m-PFSR was 58.4% (95% confidence interval [CI], 49.6%-67.1%). The median PFS and OS were 4.4 (95% CI, 3.9-5.0) months and 11.4 (95% CI, 10.3-12.5) months. In multivariate analysis, a high hazard ratio for progression was associated with target lesions located outside the lung and bone with 1.79 (95% CI, 1.10-2.93; p = 0.020). Eighty-eight AEs were recorded in 47 (37.9%) patients; the most common were pneumothorax (18/124, 14.5%), diarrhea (8/124, 6.5%), oral mucositis (7/124, 5.6%), and thrombocytopenia (7/124, 5.6%). CONCLUSIONS: Fruquintinib may be a potential option for patients with refractory sarcoma after developing several lines of TKI resistance, with a satisfactory efficacy and safety profile in combination therapy. However, the degree of contribution of fruquintinib to results is unclear when combined with other effective substances. Additional prospective trials of fruquintinib should be conducted, especially involving different pathological types and combination regimens.

11.
Eur Spine J ; 22(9): 2069-76, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23588996

RESUMO

PURPOSE: The aim of this article is to summarize our experience in treating sacral wound complications after sacrectomy. We focus, in particular, on factors associated with wound complications, including surgical site infection (SSI) and wound dehiscence. METHODS: The definition of SSI devised by Horgan et al. was applied. Wound dehiscence was defined as a wound showing breakdown in the absence of clinical signs meeting the diagnostic standard for SSI. Between September 1997 and August 2009, 387 patients with a sacral tumor underwent sacrectomy performed by the same team of surgeons and were followed up for ≥ 12 months. Potential risk factors were evaluated for univariate associations with SSI and wound complications. Multivariable conditional logistic regression was used to identify the combined effects of several risk factors. RESULTS: Of the 387 wounds studied, 274 healed uneventfully, and 113 (29.2 %) broke down because of infection or dehiscence. Fifty-one (13.2 %) patients developed a postoperative SSI, and 62 (16.0 %) patients developed wound dehiscence. Gram-negative bacteria grew in 45 cultures (91.8 %) and included 38 cases of Escherichia coli. Previous radiation, rectum rupture, longer duration of surgery, and cerebrospinal fluid leakage were significantly associated with increased likelihood of developing an SSI. Previous radiation, rectum rupture, age <40 years, history of diabetes mellitus, maximum tumor diameter ≥ 10 cm, and instrumentation used were risk factors for wound complications. CONCLUSIONS: The incidence of wound complications is not so high at a musculoskeletal tumor center with surgeons experienced in treating sacral tumors. Controlling for these risk factors when possible may improve clinical outcomes.


Assuntos
Sacro/cirurgia , Neoplasias da Coluna Vertebral/epidemiologia , Neoplasias da Coluna Vertebral/cirurgia , Deiscência da Ferida Operatória/epidemiologia , Infecção da Ferida Cirúrgica/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neoplasias de Tecido Nervoso/epidemiologia , Neoplasias de Tecido Nervoso/cirurgia , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
12.
Environ Sci Pollut Res Int ; 30(6): 15490-15504, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36169820

RESUMO

In the twenty-first century, global warming and other environmental issues have become the focus of international attention. The total generation of carbon emissions for the railway transportation industry in the BRIC countries (Brazil, Russia, Indian and China) accounted for 25.73% of the global carbon emissions in this industry during 2017. Therefore, it is necessary to identify the influencing factors of carbon emission in the railway transportation industry for the BRIC, in order to better control and reduce carbon emissions and to achieve the global goal of "net-zero emission." The logarithmic mean divisia index (LMDI) decomposition method was used to examine the factors that influenced carbon emissions from the railway transportation industry in the BRIC from 1997 to 2017. According to the findings, the total carbon emissions of the railway transportation industry in BRIC were 60.92 million tons in 2017, increased by 98.62% compared to 1997. The factor of economic output effect has contributed positively to the increase in carbon emissions in all identified countries. However, the effect of population size effect, energy structure, and transportation intensity effect for carbon emission demonstrated heterogeneity in BRIC. In addition, policy suggestions are put forward for the reduction of carbon emissions from the railway transportation industry in BRIC.


Assuntos
Dióxido de Carbono , Carbono , Carbono/análise , Dióxido de Carbono/análise , Desenvolvimento Econômico , China , Meios de Transporte
13.
Environ Sci Pollut Res Int ; 30(11): 30656-30671, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36437363

RESUMO

Carbon productivity is the core index to measure the performance of carbon emission reduction. Exploring the driving factors of the spatial-temporal differences in China's transportation sector, carbon productivity (TSCP) is conducive to the low-carbon sustainable development of the transportation sector. Based on the calculation of TSCP in 30 provinces in China from 2000 to 2019, we use time series, spatial visualization, and Dagum Gini coefficient to reveal the characteristics of spatial-temporal evolution and regional differences of TSCP, and uses Geodetector to identify the driving factors that affecting the spatial-temporal differences of TSCP. The results are as follows: (1) from 2000 to 2019, China's TSCP shows a U-shaped change trend of "decline to rise," and shows a spatial pattern of "high in the eastern and central, low in the western". (2) There are obvious regional differences in China's TSCP. The differences within each region show the trend of "eastern > central > western," while the differences between regions show the trend of "central-western > eastern-western > eastern-central," and the differences between regions are the main reason for the overall differences. (3) The spatial-temporal differences in China's TSCP are affected by many factors, such as social economy and self-endowment. Overall, energy intensity, foreign trade, technological innovation level, energy structure, and industrial structure are the dominant factors. Additionally, the interaction between the driving factors enhances the impact on the spatial-temporal differences of TSCP. Finally, according to the analysis results, some policy suggestions are put forward to improve TSCP.


Assuntos
Carbono , Desenvolvimento Econômico , Carbono/análise , Indústrias , Invenções , China , Dióxido de Carbono/análise
14.
Dalton Trans ; 52(38): 13662-13669, 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37702626

RESUMO

Current commercial lithium ion battery (LIB) anodes comprising graphite and Li4Ti5O12 inevitably suffer from safety risk and low energy density. Hence, a novel anode material of Ti0.95Nb0.95O4/C hybrid nanotubes was developed via a modified sol-gel method combined with subsequent calcination. The hybrids consist of Ti0.95Nb0.95O4 quantum dots that are homogeneously embedded in the walls of porous bamboo-like CNTs. The high capacity feature of multiple redox couples of Ti-Nb-O based anodes is demonstrated by ex situ XPS in the hybrids. With the advantages of stimulative lithium storage, increased conductivity and robust mechanical properties due to the unique hybrid structure, the hybrids exhibit a high capacity (516.8 mA h g-1 at 0.2 A g-1), superior long-term cycling stability (142.7 mA h g-1 at 5 A g-1 after 3000 cycles) and an ultra-high rate capability (234.6 mA h g-1 at 1 A g-1 and 125 mA h g-1 at 8 A g-1). Meanwhile, the hybrids showed superior electrochemical performance compared with the reported Li4Ti5O12 and Ti-Nb-O based anodes. Furthermore, the GITT measurements revealed the fast Li+ transport for the charge-discharge processes of the hybrids. Such prominent merits of the Ti0.95Nb0.95O4/C hybrid nanotubes make them more likely candidates that can replace graphite and Li4Ti5O12 anodes in LIBs.

15.
Chem Commun (Camb) ; 59(95): 14165-14168, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37955314

RESUMO

Notably, spinel Li2CuTi3O8 with higher theoretical capacity inherits the characteristics of Li4Ti5O12, which is a promising anode material for lithium ion batteries with high energy density. However, the reversible migration of Cu2+ in Li2CuTi3O8 during the discharge process limits the diffusion of Li+, resulting in poor electrochemical performance. Space confinement is a desirable successful strategy to reduce the size of electroactive materials in return for getting improved kinetics and capacity for secondary ion batteries. Here, we develop a strategy by controlling the precursor of Li2CuTi3O8 in the walls of sulfonated polymer nanotubes, and the highly crosslinked copolymer network in the process of pyrolysis caused strong space confinement for the nanoparticles, which effectively prevented the agglomeration of Li2CuTi3O8 during the calcination process. The hybrid porous nanotubes consisting of Li2CuTi3O8 nanoparticles (5-50 nm) embedded in carbon nanotubes exhibit superior performance (402.8 mA h g-1 at 0.2 A g-1, 101 mA h g-1 at 10 A g-1 after 1000 cycles). This work provides a rapid and durable Li2CuTi3O8 electrochemistry, holding great promise in developing a practically viable Li2CuTi3O8 anode and enlightening material engineering in related energy storage and conversion areas.

16.
Polymers (Basel) ; 15(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36616591

RESUMO

Epoxy (EP) was copolymerized with polyamic acid (PAA, precursor of polyimide (PI)) with termanil monomers of (1) 4,4'-Oxydianiline (ODA) and (2) pyromellitic dianhydride (PMDA) individually to form (PI-O-EP) and (PI-P-EP) copolymers. The FTIR spectrum of PI-O-EP copolymerization intermediates shows that some amide-EP linkages were formed at low temperature and were broken at higher temperature; in additoin, the released amide was available for subsequent imidization to form PI. The curing and imidization of the amide groups on PAA were determined by reaction temperature (kinetic vs. thermodynamic control). In PI-P-EP, the released amide group was very short-lived (fast imidization) and was not observed on FTIR spectra. Formation and breakage of the amide-EP linkages is the key step for EP homopolymerization and formation of the interpenetration network. PI contributed in improving thermal durability and mechanical strength without compromising EP's adhesion strength. Microphase separations were minimal at PI content less than 10 wt%. The copolymerization reaction in this study followed the "kinetic vs. thermodynamic control" principle. The copolymer has high potential for application in the field of higher-temperature anticorrosion.

17.
Front Immunol ; 14: 1087677, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37168865

RESUMO

Inflammatory bowel disease (IBD) is a group of disorders that cause chronic inflammation in the intestines, with the primary types including ulcerative colitis and Crohn's disease. The link between autophagy, a catabolic mechanism in which cells clear protein aggregates and damaged organelles, and intestinal health has been widely studied. Experimental animal studies and human clinical studies have revealed that autophagy is pivotal for intestinal homeostasis maintenance, gut ecology regulation and other aspects. However, few articles have summarized and discussed the pathways by which autophagy improves or exacerbates IBD. Here, we review how autophagy alleviates IBD through the specific genes (e.g., ATG16L1, IRGM, NOD2 and LRRK2), crosstalk of multiple phenotypes with autophagy (e.g., Interaction of autophagy with endoplasmic reticulum stress, intestinal antimicrobial defense and apoptosis) and autophagy-associated signaling pathways. Moreover, we briefly discuss the role of autophagy in colorectal cancer and current status of autophagy-based drug research for IBD. It should be emphasized that autophagy has cell-specific and environment-specific effects on the gut. One of the problems of IBD research is to understand how autophagy plays a role in intestinal tract under specific environmental factors. A better understanding of the mechanism of autophagy in the occurrence and progression of IBD will provide references for the development of therapeutic drugs and disease management for IBD in the future.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Animais , Humanos , Doenças Inflamatórias Intestinais/genética , Doença de Crohn/genética , Inflamação/complicações , Colite Ulcerativa/complicações , Autofagia/genética
18.
Org Lett ; 25(41): 7476-7480, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37811851

RESUMO

A catalytic asymmetric 1,3-acyloxy shift/polyene cyclization cascade has been achieved with good enantioselectivities under the catalysis of the chiral Au(I) reagent. The synthetic utility of this method has been showcased by the catalytic asymmetric total syntheses of (+)-2-ketoferruginol, (+)-fleuryinol B, and (+)-salviol. Notably, the first enantioselective total synthesis of (-)-erythroxylisin A has also been realized in 15 steps.

19.
Biomacromolecules ; 13(11): 3723-9, 2012 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-23016499

RESUMO

Substrate mechanical properties have remarkable influences on cell behavior and tissue regeneration. Although salt-leached silk scaffolds have been used in tissue engineering, applications in softer tissue regeneration can be encumbered with excessive stiffness. In the present study, silk-bound water interactions were regulated by controlling processing to allow the preparation of salt-leached porous scaffolds with tunable mechanical properties. Increasing silk-bound water interactions resulted in reduced silk II (ß-sheet crystal) formation during salt-leaching, which resulted in a modulus decrease in the scaffolds. The microstructures as well as degradation behavior were also changed, implying that this water control and salt-leaching approach can be used to achieve tunable mechanical properties. Considering the utility of silk in various fields of biomedicine, the results point to a new approach to generate silk scaffolds with controllable properties to better mimic soft tissues by combining scaffold preparation methods and silk self-assembly in aqueous solutions.


Assuntos
Materiais Biocompatíveis/química , Seda/química , Engenharia Tecidual , Alicerces Teciduais , Animais , Bombyx , Cloreto de Sódio
20.
Medicine (Baltimore) ; 101(40): e30947, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36221393

RESUMO

Intra-aortic balloon occlusion (IABO) is used to reduce intraoperative bleeding and facilitate successful sacrum tumor resection. Up to 20% of patients experience postoperative wound healing problems, but the risk factors related to this complication have not been clearly defined. The anesthetic database of Peking University People's Hospital, Beijing, China, was searched for all patients (aged 14-70 years old) who underwent sacrum tumor surgery with the application of IABO from 2014 to 2017. Data from 278 patients with an aortic occlusion duration of 72 ± 33 minutes were collected. Fifty-six patients required postoperative debridement because of wound infection. The independent risk factor identified by logistic regression was fluid excess (calculated as volume infused minus blood loss and urine output divided by body weight [kg]), and decision tree analysis revealed that the cutoff point for fluid excess was 38.5 mL/kg. Then patients were then divided into high fluid excess group (fluid excess > 38.5 mL/kg) and low fluid excess group (fluid excess ≤ 38.5 mL/kg) and 91 pairs of patients were generated through propensity score matching (PSM). Fluid excess was significantly higher in the high fluid excess group (46 vs 30 mL/kg, P < .001), and more patients required postoperative debridement than in the low fluid excess group (24 (26.3%) vs 12 (13.1%), P < .001). In this retrospective PSM study on sacrum tumor resection, fluid overload was related to postoperative debridement and further studies are needed to improve the clinical prognosis.


Assuntos
Insuficiência Cardíaca , Neoplasias , Desequilíbrio Hidroeletrolítico , Adolescente , Adulto , Idoso , Desbridamento/efeitos adversos , Insuficiência Cardíaca/complicações , Humanos , Pessoa de Meia-Idade , Neoplasias/complicações , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Pontuação de Propensão , Estudos Retrospectivos , Sacro/cirurgia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA