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1.
Viruses ; 16(1)2024 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-38275956

RESUMO

Sapovirus (SaV) is a type of gastroenteric virus that can cause acute gastroenteritis. It is highly contagious, particularly among children under the age of 5. In this study, a total of 712 stool samples from children under the age of 5 with acute gastroenteritis were collected. Out of these samples, 28 tested positive for SaV, resulting in a detection rate of 3.93% (28/712). Samples with Ct < 30 were collected for library construction and high-throughput sequencing, resulting in the acquisition of nine complete genomes. According to Blast, eight of them were identified as GI.1, while the remaining one was GI.6. The GI.6 strain sequence reported in our study represents the first submission of the GI.6 strain complete genome sequence from mainland China to the Genbank database, thus filling the data gap in our country. Sequence identity analysis revealed significant nucleotide variations between the two genotypes of SaV and their corresponding prototype strains. Phylogenetic and genetic evolution analyses showed no evidence of recombination events in the obtained sequences. Population dynamics analysis demonstrated potential competitive inhibition between two lineages of GI.1. Our study provides insights into the molecular epidemiological and genetic evolution characteristics of SaV prevalent in the Nantong region of China, laying the foundation for disease prevention and control, as well as pathogen tracing related to SaV in this area.


Assuntos
Infecções por Caliciviridae , Gastroenterite , Sapovirus , Criança , Humanos , Pré-Escolar , Sapovirus/genética , Filogenia , Gastroenterite/epidemiologia , Genótipo , Genômica , Infecções por Caliciviridae/epidemiologia , Fezes
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(3): 693-698, 2023 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-37356928

RESUMO

OBJECTIVE: To investigate the clinical characteristics, therapeutic response and prognosis of patients with plasma cell leukemia (PCL) and improve the understanding of this disease. METHODS: The clinical manifestations, laboratory tests and treatment response of 27 patients with plasma cell leukemia treated in The Second Hospital of Shanxi Medical University from December 2010 to August 2019 were analyzed retrospectively, and their clinical characteristics were summarized. Kaplan-Meier method was used for survival analysis. RESULTS: There were 18 cases of primary plasma cell leukemia (pPCL) and 9 cases of secondary plasma cell leukemia (sPCL). The male to female ratio was 1.7∶1. The median age was 62 years old. The first manifestations were bone pain, fatigue, fever, splenomegaly and bleeding, and a large number of plasma cell infiltration was observed in the morphological examination of peripheral blood and bone marrow cells. 13 cases were detected by immunotyping and all of them expressed CD38/CD138. 8 cases underwent karyotype analysis, and 3 cases were normal, clonal abnormalities occurred in 5 cases. FISH detection was performed in 12 cases, of which 8 cases were abnormal. In 17 cases of bortezomib based chemotherapy, the ovevall response rate was 52.9%, which was higher than that in the non-bortezomib group, but there was no significant difference between the two groups (P =0.242). The overall median survival time of 27 patients was 6.4 months, the median progression-free survival time was 3.5 months, and the median survival time of patients with pPCL and sPCL was 8.2 months and 2.4 months, respectively, the difference between the two groups was statistically significant (P =0.031). CONCLUSION: PCL is highly invasive and has diverse clinical manifestations, and is not sensitive to traditional chemotherapy. The median survival time of patients with pPCL is relatively longer than that of patients with sPCL. The chemotherapy regimen based on bortezomib improves the treatment effectiveness and prolongs the survival time of PCL patients.


Assuntos
Leucemia Plasmocitária , Masculino , Feminino , Humanos , Leucemia Plasmocitária/diagnóstico , Estudos Retrospectivos , Bortezomib/uso terapêutico , Prognóstico , Análise de Sobrevida
3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(2): 476-482, 2023 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-37096522

RESUMO

OBJECTIVE: To investigate the clinical characteristics, prognostic factors and efficacy of hypomethylating agent (HMA) in patients with chronic myelomonocytic leukemia (CMML). METHODS: The clinical data of 37 newly diagnosed patients with CMML was analyzed retrospectively, and their clinical characteristics and the efficacy of HMA were summarized. Kaplan-Meier and Log-rank test were used for univariate survival analysis, and Cox proportional hazards regression model was used for multivariate analysis. RESULTS: The median age at diagnosis was 67 years old. Their common manifestations included fatigue, bleeding, abnormal blood routine and fever. Most patients had splenomegaly. According to FAB classification, there were 6 cases of myelodysplastic CMML and 31 cases of myeloproliferative CMML, while according to WHO classification, 8 patients belonged to CMML-0, 9 patients to CMML-1 and 20 patients to CMML-2. At the time of diagnosis, the median white blood cell count was 32.84×109/L, median hemoglobin (Hb) was 101 g/L, median platelet count was 65×109/L, median absolute monocyte count was 9.53×109//L, median absolute neutrophil count (ANC) was 11.29×109//L and median lactate dehydrogenase (LDH) was 374 U/L. Cytogenetic abnormalities were found in 4 cases among the 31 patients who underwent karyotype analysis or fluorescence in situ hybridization detection. There were 12 patients who had analyzable results and gene mutations were identified in 11 cases, including ASXL1, NRAS, TET2, SRSF2 and RUNX1. Among the 6 patients who were treated with HMA and could be evaluated for efficacy, 2 patients achieved complete remission, 1 patient achieved partial remission and 2 patients achieved clinical benefit. Compared with the non-HMA treatment group, overall survival (OS) time was not significantly prolonged in the HMA treatment group. Univariate analysis showed that Hb<100 g/L, ANC≥12×109/L, LDH≥250 U/L and peripheral blood (PB) blasts ≥5% were significantly associated with poor OS, while WHO classification CMML-2, Hb<100 g/L, ANC≥12×109/L, LDH≥250 U/L and PB blasts≥5% were significantly associated with poor leukemia-free survival (LFS) (P<0.05). Multivariate analysis showed that ANC≥12×109/L and PB blasts≥5% were significantly associated with poor OS and LFS (P<0.05). CONCLUSION: CMML has high heterogeneity in clinical characteristics, genetic changes, prognosis and treatment response. HMA can not significantly improve the survival of CMML patients. ANC≥12×109/L and PB blasts≥5% are independent prognostic factors of OS and LFS in patients with CMML.


Assuntos
Leucemia Mielomonocítica Crônica , Humanos , Idoso , Leucemia Mielomonocítica Crônica/genética , Estudos Retrospectivos , Hibridização in Situ Fluorescente , Análise de Sobrevida , Prognóstico
4.
Materials (Basel) ; 16(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36770261

RESUMO

Adding organically modified bentonite into impervious wall materials may improve the adsorption of organic pollutants. In this study, cetyltrimethylammonium bromide organically modified bentonite (CTMAB bentonite) was mixed with sodium bentonite and kaolin to obtain two materials, which were then used as cut-off walls for typical pollutants. Soil column consolidation tests, diffusion tests, and breakdown tests were conducted to study migration of organic pollutants in soil columns. The parameter sensitivity of pollutant transport in the cut-off wall was analysed by numerical simulation. The sodium bentonite mixed with 10% CTMAB bentonite and kaolin-CTMAB bentonite showed the greatest impermeability: with a consolidation pressure of 200 kPa, the permeability coefficients were 1.03 × 10-8 m/s and 3.49 × 10-9 m/s, respectively. The quantity of phenol adsorbed on sodium bentonite-CTMAB bentonite increased with increasing water head height. The kaolin-CTMAB bentonite column showed the best rhodamine B adsorption performance, and the adsorption rate reached 98.9% on day 67. The numerical results showed that the permeability coefficient was positively correlated with the diffusion of pollutants in the soil column. The quantity adsorbed on the soil column was positively correlated with the retardation factor, and the extent of pollutant diffusion was negatively correlated with the retardation factor. This study provides a technical means for the optimal design of organic pollutant cut-off walls.

5.
J Hazard Mater ; 446: 130680, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36592557

RESUMO

Development of co-processing technology in the cement industry in China is important for environmentally sound disposal and recycling of waste, and contributes to sustainable development of the cement industry. However, dioxin pollution could negatively affect promotion of this technology. Therefore, it is necessary to study the emission characteristics of dioxins in cement kilns. In this study, the emission characteristics of dioxins and factors influencing their generation during co-processing solid wastes were studied in 14 new dry cement kilns. The dioxin concentrations were very similar regardless of whether solid wastes were fed into the kiln. In blank runs without co-processing, the average dioxin concentration was 0.0097 ng international toxic equivalents (I-TEQ)/Nm3. By comparison, that for co-processing solid wastes was 0.012 ng I-TEQ/Nm3. These values meet the relevant emission standards. The type of co-processed solid wastes had almost no effect on the dioxin concentration. At larger production scales, the concentration of dioxin emitted in the flue gas decreased. The dioxin concentrations in kiln dust were obviously higher than those in clinker and raw materials. The average emission factor of dioxin per ton of cement was 30 ng I-TEQ/t, which is equivalent to that in cement kilns in other countries.

6.
BMC Anesthesiol ; 22(1): 216, 2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35820840

RESUMO

BACKGROUND: Laryngeal mask airway(LMA) have been widely used in clinical practice. Irritation to the patient during the insertion of a laryngeal mask can cause hemodynamic fluctuations, which is particularly unsafe for geriatric patients. We used probit regression analysis to determine the median effective dose of sufentanil to inhibit the response to LMA insertion in geriatric patients. METHODS: A total of 90 patients were selected for the study using the following inclusion criteria: age ≥ 65 years old, ASA grade I-III, and scheduled to undergo intravenous general anesthesia with LMA insertion. Each patient received a dose of sufentanil for anesthesia induction in one of six levels: 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 µg kg-1. LMA insertion was scored with a 3-point, 6-category scale, with scores ≥ 16 indicating effective LMA insertion, and < 16 indicating ineffective LMA insertion. Mean arterial blood pressure (MAP), heart rate (HR), and bispectral index (BIS) were recorded 1 min before induction (T1), 1 min after induction (T2), 1 min after LMA insertion (T3), and 5 min after LMA insertion (T4) in each group. In addition, the plasma norepinephrine (NE) levels and adverse reactions were measured at T2 and T3 in each dosage group. RESULTS: Probit regression analysis showed that the ED50 of sufentanil inhibiting the response to LMA insertion in geriatric patients was 0.18 µg kg-1 (95% CI: 0.16-0.21 µg kg-1), and the ED95 was 0.31 µg kg-1 (95% CI: 0.27-0.38 µg kg-1), and the probit(p) = -2.34 + 12.90 × ln(Dose)([Formula: see text] = 0.725, p = 0.948). Among all the patients, the number of effective LMA insertions was 57 (group A), and the number of ineffective LMA insertions was 33 (group B). The MAP, HR, and NE in group B were significantly higher than in group A at T3. CONCLUSIONS: Sufentanil can effectively inhibit the patient's response to LMA insertion, with stable hemodynamics and small stress response. The ED50 and ED95 were 0.18 µg kg-1 (95% CI: 0.16-0.21 µg kg-1) and 0.31 µg kg-1(95% CI: 0.27-0.38 µg kg-1), respectively. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100051827 ) on October 6, 2021.


Assuntos
Máscaras Laríngeas , Idoso , Anestesia Geral , Anestesia Intravenosa , Método Duplo-Cego , Humanos , Estudos Prospectivos , Sufentanil
7.
Materials (Basel) ; 15(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35744117

RESUMO

Organic dye rhodamine B is one of the common organic pollutants in the water and soil environment. This study investigated the feasibility of removing rhodamine B from an aqueous solution through adsorption by kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite. Batch adsorption test results showed that the maximum adsorption quantities of kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite were 7.76 mg/g, 11.26 mg/g, and 12.68 mg/g, respectively, implying that the addition of bentonite to kaolin can effectively improve its adsorption capacity for rhodamine B. Moreover, the Langmuir isotherm model is suitable to describe the adsorption of rhodamine B by kaolin and kaolin-sodium bentonite, while it is preferable to use the Freundlich isotherm model in the case of kaolin-organic bentonite. The adsorption kinetic characteristics of rhodamine B, by these three adsorbents, are suitable to be described with a pseudo-second order kinetic model. Furthermore, the characteristics of the above three adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The above results indicated that kaolin and organic bentonite can be used to design efficient adsorbents for organic pollutants similar to rhodamine B.

8.
Polymers (Basel) ; 13(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200957

RESUMO

The investigation of gas transport in fractured porous media is essential in most petroleum and chemical engineering. In this paper, an apparent gas permeability model for real gas flow in fractured porous media is derived with adequate consideration of real gas effect, the roughness of fracture surface, and Knudsen diffusion based on the fractal theory. The fractal apparent gas permeability model is obtained to be a function of micro-structural parameters of fractured porous media, relative roughness, the pressure, the temperature, and the properties of gas. The predictions from the apparent gas permeability model based on the fractal theory match well with the published permeability model and experimental data, which verifies the rationality of the present fractal apparent gas permeability model.

9.
Polymers (Basel) ; 14(1)2021 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-35012105

RESUMO

Against the background of people's increasing awareness of personal safety and property safety, the flame retardancy (FR) of materials has increasingly become the focus of attention in the field of construction engineering. A variety of materials have been developed in research and production in this field. Polymers have many advantages, such as their light weight, low water absorption, high flexibility, good chemical corrosion resistance, high specific strength, high specific modulus and low thermal conductivity, and are often applied to the field of construction engineering. However, the FR of unmodified polymer is not ideal, and new methods to make it more flame retardant are needed to enhance the FR. This article primarily introduces the flame-retardant mechanism of fire retardancy. It summarizes the preparation of polymer flame-retardant materials by adding different flame-retardant agents, and the application and research progress related to polymer flame-retardant materials in construction engineering.

10.
J Investig Med High Impact Case Rep ; 8: 2324709620961613, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32964755

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by heterogeneous symptoms that can manifest in any organ, and often presents at a young age. Infectious mononucleosis (IM) is the acute clinical manifestation of Epstein-Barr virus (EBV). It is characterized by low-grade fever, malaise, lymphadenopathy, splenomegaly, and occasionally symmetrical arthralgias. It has been proposed that EBV is a trigger for new-onset SLE, and patients with autoimmune disorders such as SLE are more likely to have recurrent IM infections. The patient, a 64-year old Caucasian female who's only past medical history was hypertension, developed several months-long period of vague symptoms, including fatigue, malaise, nausea, and nonbilious vomiting with oral intake. She presented with symmetrical polyarthritis involving the hands and elbows, with no history of arthritis before this episode. At the 5-month follow-up, she presented with worsening arthritis bilaterally in her elbows and in her right knee. For several decades, there has been a theoretical association between EBV and SLE, with EBV thought to be one of the many possible triggers for development of SLE. Based on the disease course, we theorize that the patient's IM and EBV infection led to development of SLE. A small fraction of SLE cases have been reported in literature to be associated with EBV. This case adds to that literature with EBV triggering development of SLE in a seemingly previously asymptomatic patient.


Assuntos
Mononucleose Infecciosa/complicações , Mononucleose Infecciosa/diagnóstico , Lúpus Eritematoso Sistêmico/diagnóstico , Anticorpos Antivirais/análise , Feminino , Herpesvirus Humano 4/imunologia , Humanos , Pessoa de Meia-Idade
11.
J Org Chem ; 85(19): 12408-12417, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-32885655

RESUMO

In view of the importance of both fluorinated synthons and homoenolate equivalents, synthetic application of difluorocyclopropanols is desired but remains challenging due to their thermodynamic instability. Herein, we use siloxydifluorocyclopropanes as difluorocyclopropanol precursors to carry out new Cu-catalyzed ring-opening defluorinative alkylation. With α-bromo carboxylic esters as coupling partners, the reaction affords γ-fluoro-δ-ketoesters via a CuI/CuII catalytic cycle. Interestingly, by the use of α-bromoamides, the ring-opening defluorinative alkylation is followed by an additional intramolecular C-N oxidative coupling to deliver a lactam intermediate, which further undergoes defluorination, hydrolysis, ring opening, and dehydration cascade via a CuI/CuII/CuIII catalytic pathway, leading to γ,δ-diketonitriles as the final products.

12.
Sensors (Basel) ; 20(17)2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32858981

RESUMO

This paper illustrates a simple yet effective spectroscopic technique for the prediction of soil organic matter (SOM) from moist soil through the synchronous 2D correlation spectroscopy (2D-COS) analysis. In the moist soil system, the strong overlap between the water absorption peaks and the SOM characteristic features in the visible-near infrared (Vis-NIR) spectral region have long been recognised as one of the main factors that causes significant errors in the prediction of the SOM content. The aim of the paper is to illustrate how the tangling effects due to the moisture and the SOM can be unveiled under 2D-COS through a sequential correlogram analysis of the two perturbation variables (i.e., the moisture and the SOM) independently. The main outcome from the 2D-COS analysis is the discovery of SOM-related bands at the 597 nm, 1646 nm and 2138 nm, together with the predominant water absorbance feature at the 1934 nm and the relatively less important ones at 1447 nm and 2210 nm. This information is then utilised to build partial least square regression (PLSR) models for the prediction of the SOM content. The experiment has shown that by discarding noisy bands adjacent to the SOM features, and the removal of the water absorption bands, the determination coefficient of prediction (Rp2) and the ratio of prediction to deviation (RPD) for the prediction of SOM from moist soil have achieved Rp2 = 0.92 and the RPD = 3.19, both of which are about 5% better than that of using all bands for building the PLSR model. The very high RPD (=3.19) obtained in this study may suggest that the 2D-COS technique is effective for the analysis of complex system like the prediction of SOM from moist soil.

13.
EJHaem ; 1(1): 309-311, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35847739

RESUMO

Advent of tyrosine kinase inhibitors (TKI) have revolutionized therapy of chronic myeloid leukemia. Imatinib was the first agent utilized in the therapy of CML. Nilotinib, a second generation TKI, results in an increase in number of patients achieving major molecular response at an earlier time point. Asymptomatic elevations in pancreatic enzyme is common and acute pancreatitis within weeks to months from start of therapy has been observed. Delayed onset pancreatitis has not been reported. We report a case of delayed onset pancreatitis in a patient with sustained complete molecular response. On account of the deep response, we were able to avoid starting alternate tyrosine kinase inhibitors that could also result in pancreatitis as a class effect.

14.
J Hazard Mater ; 377: 98-105, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31153118

RESUMO

In this study, we propose a novel strategy, plasma activated water (PAW) to reduce pesticide residues on agricultural products. To validate its feasibility and effectiveness, we employee high-performance liquid chromatography (HPLC) to detect phoxim on grapes. HPLC results suggest that the reduction of phoxim on grapes achieve 73.60% after treated 10 min by PAW prepared 30 min, and the concentration of phoxim decreased significantly (p <  0.05) with the preparation time of PAW. Furthermore, HPLC-MS analysis shows that the reduction effect of phoxim by PAW is dominated by the degradation of phoxim. Combined with analyzing the physicochemical properties of PAW, one possible degradation pathway is proposed under the present experimental conditions, mediated by reactive oxygen and nitrogen species. The acidic environment (pH < 3) and high oxidation capacity (ORP > 500 mV) are suggested to be a benefit to the reduction of phoxim. Besides, the experimental results regarding color, firmness, sugar, vitamin C, and superoxide dismutase of grapes demonstrate that the PAW treatment will not significantly affect the quality of grapes. In conclusion, phoxim pesticide residues on grapes could be effectively reduced by the PAW strategy and without a significant (p <  0.05) effect on grapes quality.


Assuntos
Inseticidas/isolamento & purificação , Compostos Organotiofosforados/isolamento & purificação , Resíduos de Praguicidas/isolamento & purificação , Vitis/química , Água/química , Ácido Ascórbico/análise , Cromatografia Líquida de Alta Pressão , Cor , Concentração de Íons de Hidrogênio , Inseticidas/química , Espectrometria de Massas , Compostos Organotiofosforados/química , Resíduos de Praguicidas/química , Espécies Reativas de Nitrogênio , Espécies Reativas de Oxigênio , Açúcares/análise , Superóxido Dismutase/análise
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(10): 3249-53, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-30246948

RESUMO

Soil moisture shows a strong absorption for spectroscopy while soil organic matter and moisture have identical absorption bands. Therefore, the soil moisture causes interference to soil organic matter detection. The study made the following works: firstly, different soil organic matter dynamic spectrums under different moisture content were acquired with visible near-infrared spectroscopy; secondly, different organic matter content features under the same moisture content were analyzed with two-dimensional synchronization correlation spectroscopy. When the soil moisture is 0%, around 600 and 1 660 nm which characterize soil organic matter band appear strong autocorrelation peaks. With moisture content increasing, around 600 and 1 660 nm band disappear and around 1 931, 2 200 and 1 480 nm band appear strong autocorrelation peaks in the near-infrared region. Soil moisture covers information bands which characterize soil organic matter and affects soil organic matter detection; thirdly, the maximum moisture content samples approximately in the filed participated modeling to eliminate the effect of moisture on soil organic matter detection and improve the model prediction accuracy. The anti-moisture interference prediction model which used 550~650 and 1 610~1 710 nm wavelengths by PLS (Partial Least Squares) quantitative analysis method was established to predicate the soil organic matter content under different moisture content. The results are as follows: predicted correlation coefficient, SEP and RMSEP is 0.954, 0.744 and 0.844 respectively. Predicted effect improves significantly. It is that the method can reduce the effect of moisture on soil organic matter detection.

16.
J Biomater Sci Polym Ed ; 21(6-7): 863-76, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20482989

RESUMO

The data for long-term drug-delivery systems are scarce compared to the short-term systems because the required research efforts are more time-consuming. In this study, we report a novel cross-linked composite based on poly(vinyl alcohol) (PVA) containing cupric ions for long-term delivery, which is helpful for contraception and trace element balance in the human body. The composition, corrosion products, crystal structure, chemical structure and mechanical stability of the composite, after being immersed in simulated body fluid (SBF) for one year, were studied by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR) and mechanical testing. The results show that no other new elements, such as P, Cl and Ca, appear on the surface of the composite and no Cu(2)O was formed after immersion in SBF for one year. The effectiveness of copper can be greatly improved and the side-effects caused by these compounds might also be eliminated. Furthermore, this novel composite exhibits long-term mechanical stability in SBF. The present in vitro long-term data suggest that this novel copper-containing composite may serve as a substitute for conventional materials of copper-containing intrauterine devices (Cu-IUDs) and as a carrier for controlled-release material in a variety of other applications.


Assuntos
Materiais Biocompatíveis/química , Cobre/química , Álcool de Polivinil/química , Líquidos Corporais/química , Corrosão , Reagentes de Ligações Cruzadas , Sistemas de Liberação de Medicamentos , Humanos , Dispositivos Intrauterinos , Teste de Materiais , Difração de Raios X
17.
J Zhejiang Univ Sci ; 4(6): 683-93, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14566984

RESUMO

Pile drivability is a key problem during the stage of design and construction installation of pile foundations. The solution to the one dimensional wave equation was used to determine the impact force at the top of a concrete pile for a given ram mass, cushion stiffness, and pile impedance. The kinematic equation of pile toe was established and solved based on wave equation theory. The movements of the pile top and pile toe were presented, which clearly showed the dynamic displacement, including rebound and penetration of pile top and toe. A parametric study was made with a full range of practical values of ram weight, cushion stiffness, drop eight, and pile impedance. Suggestions for optimizing the parameters were also presented. Comparisons between the results obtained by the present solution and in-situ measurements indicated the reliability and validity of the method.


Assuntos
Arquitetura de Instituições de Saúde/métodos , Modelos Teóricos , Elasticidade , Arquitetura de Instituições de Saúde/instrumentação , Estresse Mecânico
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