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1.
Artigo em Chinês | MEDLINE | ID: mdl-35680579

RESUMO

Objective: To understand the incidence of pneumoconiosis in the non-coal mining industry in Jiangsu Province, and provide reference for the prevention and control of pneumoconiosis in the non-coal mining industry. Methods: The data of 7019 newly diagnosed pneumoconiosis patients in non-coal mining industry in Jiangsu Province from January 1956 to December 2019 were collected through the Jiangsu Province Pneumoconiosis Follow-up Network Report System, including the gender of the pneumoconiosis patients, the name of the employer and the location, the industry classification of the employer, the duration of dust exposure in dust exposure, the name of occupational pneumoconiosis disease, the date of diagnosis of pneumoconiosis, etc. The collected case data of patients with pneumoconiosis were entered into the statistical software, and the characteristics of the patients' diagnosis time, region and industry were analyzed. Results: The number of confirmed pneumoconiosis patients in the non-coal mining industry in Jiangsu Province was mostly in 2007 (395 cases) , concentrated in Wuxi City (40.96%, 2875/7019) and Suzhou City (27.72%, 1946/7019) . The industries to which the patients belonged were mainly non-metallic mining and dressing (60.95%, 4278/7019) , and the most common type of pneumoconiosis was silicosis (96.40%, 6766/7019) . The patients were mainly stageⅠpneumoconiosis (61.33%, 4305/7019) . There were statistically significant differences in the mean age of diagnosis and the average duration of dust exposure among patients with different pneumoconiosis stages (P<0.01) . The differences in the average diagnosis age and the average duration of dust exposure of patients with different types of pneumoconiosis were statistically significant (P<0.05) , the mean age of diagnosis and the average duration of dust exposure of electric welders were the smallest, which were (44.92±7.74) years old and (17.38±10.15) years, respectively. Conclusion: The regional and industry distribution characteristics of new pneumoconiosis patients in the non-coal mining industry in Jiangsu Province are obvious, and attention should be paid to the treatment of pneumoconiosis patients with young diagnosed age and short duration of dust exposure, as well as the personal protection and health protection of front-line workers such as electric welders who are exposed to productive dust in a short period of time.


Assuntos
Minas de Carvão , Doenças Profissionais , Exposição Ocupacional , Pneumoconiose , Silicose , Adulto , Poeira , Humanos , Pessoa de Meia-Idade , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Pneumoconiose/diagnóstico , Pneumoconiose/epidemiologia , Silicose/epidemiologia
3.
Eur Rev Med Pharmacol Sci ; 22(17): 5747-5754, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30229853

RESUMO

Multiple sclerosis (MS) is an inflammatory idiopathic autoimmune disease causing demyelination of central nervous system (CNS). The incidence of pediatric MS is relatively rare, affecting 0.2 to 0.64/100,000 subjects; cases with MS onset before age 10-12 years, account for less than 1% of all MS cases, while 2.7 to 10.5% of all MS cases worldwide are seen in children <18 years of age, with a strong female preponderance. The disease course of MS varies from a benign type with relatively low level of disability after a long duration (15 years) of the disease, to a malignant type of MS with severe disability or even death within few months following onset. Diagnostic criteria for pediatric MS include ≥ 2 clinical events involving more areas of CNS inflammation in the absence of encephalopathy, separated by > 30 days, along with the involvement of brainstem. Pediatric MS generally presents relapsing-remittent form of MS, with majority of the patients recovering from the first attack. Major histocompatibility complex, more specifically, mutations in the human leukocyte antigen (HLA) DRB1*15 allele, are considered most important genetic factors that are contributory to the disease. Treatment choices for pediatric MS include many disease-modifying therapies (DMT) that are currently being used for adult MS and these are interferon-ß 1a/1b (IFN-ß1a/1b), glatiramer acetate, teriflunomide, dimethyl fumarate, alemtuzumab, etc. However, most of these have not gone through complete testing in randomized, placebo-controlled clinical trials for pediatric MS and are being prescribed off-label by clinicians. As these studies are progressing, it is important to address if these approaches of treating pediatric MS patients have any long-term impact on patients, in particular, physical, cognitive, developmental and social outcomes of the children.


Assuntos
Fatores Imunológicos/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Adolescente , Idade de Início , Criança , Tomada de Decisão Clínica , Progressão da Doença , Feminino , Predisposição Genética para Doença , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Humanos , Fatores Imunológicos/efeitos adversos , Masculino , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/epidemiologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Mutação , Seleção de Pacientes , Fenótipo , Indução de Remissão , Fatores de Risco , Resultado do Tratamento
4.
Eur Rev Med Pharmacol Sci ; 22(12): 3971-3975, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29949172

RESUMO

OBJECTIVE: To investigate the effect of sevoflurane on cognitive function and inflammatory response of children after general anesthesia at different times. PATIENTS AND METHODS: Ninety-three pediatric patients who underwent general anesthesia surgery were enrolled and divided into groups based on time under general anesthesia: group A (<1 h, n=27), group B (1-3 h, n=36), and group C (≥ 3 h, n=30). Changes in cognitive function and serum inflammatory index were compared. RESULTS: The occurrence of postoperative cognitive dysfunction (POCD) in group A and B was lower than in group C and the difference was statistically significant (p<0.05). The levels of caspase-3, TNF-α, and IL-6 in the POCD group at the different time points were significantly higher than in the non-POCD group and the differences were statistically significant (p<0.05). Caspase-3, TNF-α, and IL-6 levels in the POCD group at the different time points significantly changed and were highest during the recovery period, while there were no significant changes in the non-POCD group at the different time points. CONCLUSIONS: The prolonged sevoflurane inhalational anesthesia time (≥ 3 h) enhanced the occurrence of POCD and was related to the expression levels of serum caspase-3, TNF-α, and IL-6.


Assuntos
Disfunção Cognitiva/etiologia , Inflamação/etiologia , Complicações Pós-Operatórias/etiologia , Sevoflurano/efeitos adversos , Adolescente , Anestesia por Inalação/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Interleucina-6/sangue , Masculino , Fator de Necrose Tumoral alfa/sangue
6.
Eur Rev Med Pharmacol Sci ; 21(4 Suppl): 120-125, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29165751

RESUMO

OBJECTIVE: To further guide the standardized training work of the resident doctor and apply critical pathway management to resident doctor's standardized training. MATERIALS AND METHODS: The traditional training contents were adjusted. The main research content of evaluating the results of standardized training was designed, and the research method was adopted by the standardized training of the resident doctor. RESULTS: The resident doctors of the group with the new teaching method demonstrated a high participation rate. Because of the constraint of the standardized training, trainers would pay more attention to their training. CONCLUSIONS: The clinical pathway polishes up the ability of resident doctors, further guiding the standardized training work of a resident doctor.


Assuntos
Procedimentos Clínicos , Internato e Residência/normas , Pediatria/educação , Pressão Sanguínea/fisiologia , Criança , Eletrocardiografia , Humanos , Avaliação de Programas e Projetos de Saúde
7.
Eur Rev Med Pharmacol Sci ; 21(4 Suppl): 37-42, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29165767

RESUMO

OBJECTIVE: To compare the influence of laryngeal mask airway (LMA) insertion anesthesia and endotracheal intubation on cognitive function during anesthesia for neurosurgery microscopy. PATIENTS AND METHODS: A total of 76 pediatric patients who underwent neurosurgery microscopy were selected. They were randomly divided in the LMA insertion group with 35 cases and the endotracheal intubation group with 41 cases. Before the operation, the two groups were injected with 0.02 mg/kg atropine and 2 mg/kg phenobarbital. A combination solution of 2 mg/kg ketamine and 0.1 mg/kg midazolam was then given to induce anesthesia. The inhalation of 4-6% sevoflurane was used to maintain anesthesia. The hemodynamics, complications, cognitive functions, and expression levels of serum NSE and S-100ß protein after anesthesia and extubation were compared. RESULTS: After comparing the average heart rate, average arterial pressure and average oxygen saturation of the LMA insertion group at different times, the difference was not statistically significant (p>0.05). At T2 and T4, compared with the endotracheal intubation group, the average heart rate and arterial pressure of the LMA insertion group were significantly reduced and the average oxygen saturation was significantly increased. The difference was statistically significant (p<0.05). The prevalence of complications from postoperative cognitive dysfunction (POCD) of the LMA insertion group was significantly lower than that of the endotracheal incubation group. The difference was statistically significant (p<0.05). CONCLUSIONS: Compared with the endotracheal intubation group, in the LMA insertion group, the hemodynamics is more stable, the prevalence of postoperative complications and the POCD are lower during pediatric neurosurgery microscopy. The occurrence of POCD is related to the reduction of protein expression levels of NSE and S-100ß during serum anesthesia and the recovery period.


Assuntos
Anestesia/métodos , Cognição , Intubação Intratraqueal/efeitos adversos , Máscaras Laríngeas/efeitos adversos , Microcirurgia/métodos , Neurocirurgia/métodos , Complicações Pós-Operatórias/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Feminino , Hemodinâmica , Humanos , Lactente , Masculino , Fosfopiruvato Hidratase/sangue , Subunidade beta da Proteína Ligante de Cálcio S100/sangue
8.
Eur Rev Med Pharmacol Sci ; 21(4 Suppl): 31-36, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29165768

RESUMO

Leukemia is defined as an aberrant hyper-proliferation of immature blood cells that do not form solid tumor masses (i.e., liquid cancer). Usually, leukemia could be either of the myeloid or lymphoid lineages, and is classified as acute or chronic in nature. Chronic leukemias tend to have more mature cells and are rare in pediatric patients. Acute leukemias, on the other hand, are typically less mature and commonly occur in patients of all ages and are potentially rapidly fatal if not readily treated. The acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Similar to AML, and in some cases, on the same disease spectrum, are the myelodysplastic syndromes (MDS). The present review is focused on the recent perspectives of pediatric leukemia.


Assuntos
Leucemia/classificação , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Doença Aguda , Doença Crônica , Humanos , Leucemia/tratamento farmacológico , Leucemia/genética , Leucemia/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Prognóstico , Fatores de Risco
9.
Eur Rev Med Pharmacol Sci ; 21(4 Suppl): 20-24, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29165770

RESUMO

Advancements in pediatric cancers diagnostics clarity and treatments have greatly increased survival rates in the pediatric oncology population. Increased survival rates have turned new attention to studying psychosocial stressors and improvisation of the quality of life of the suffering cancer patients. The cancer treatment experience could be divided into three phases: diagnosis, treatment, and post-treatment/survivorship. The present review article would focus specifically on the three most common pediatric cancer diagnostic categories viz. acute lymphoblastic leukemia (ALL), central nervous system (CNS) tumors, and neuroblastoma.


Assuntos
Sobreviventes de Câncer/psicologia , Neoplasias do Sistema Nervoso Central/diagnóstico , Neoplasias do Sistema Nervoso Central/terapia , Neuroblastoma/diagnóstico , Neuroblastoma/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Humanos , Qualidade de Vida
10.
Artigo em Chinês | MEDLINE | ID: mdl-27682487

RESUMO

Objective: To investigate the health status of workers exposed to zircon sand and silica dust in a precision casting enterprise, and to provide a basis for the development of prevention and control measures. Methods: Occupational health examination, questionnaire survey, and field investigation of occupational health were performed for 176 male workers (18 workers in the zirconium dust exposure group, 109 in the non-zirconium dust exposure group, and 49 in the non-dust exposure group) in a precision casting enterprise, and a statistical analysis was performed for the data obtained. Results: Dust and noise were major hazard factors for occupational diseases in this enterprise. The abnormal rate of physical examination was 71.02%. Compared with the non-zirconium dust exposure group, the zirconium dust exposure group had significantly higher detection rates of restrictive ventilatory dysfunction, increased immunoglobulin IgE, increased alanine aminotransferase, and increased alkaline phosphatase (ALP) (P<0.05) ; compared with the non-dust exposure group, the zirconium dust exposure group had a significantly higher detection rate of increased ALP (P<0.05) . Of all workers, 15 were found to have pneumoconiosis-like changes (11 had pneumoconiosis and 4 needed observation) , among whom 4 were in the zirconium dust exposure group (3 had pneumoconiosis and 1 needed observation) and 11 were in the non-zirconium dust exposure group (8 had pneumoconiosis and 3 needed observation) . The detection rate of pneumoconiosis-like changes showed no significant differences between the two groups (20.22% vs 10.09%) . Conclusions: There was a severe dust hazard in this enterprise. Inhalation of dust containing zirconium is associated with respiratory system injury, especially the development of pneumoconiosis, and it may also cause immune dysfunction and liver impairment.


Assuntos
Poeira , Exposição por Inalação/efeitos adversos , Doenças Profissionais , Nível de Saúde , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Pneumopatias , Masculino , Pneumoconiose/prevenção & controle , RNA Polimerase I , Estudos Retrospectivos , Silicatos/efeitos adversos , Dióxido de Silício/efeitos adversos , Inquéritos e Questionários , Zircônio/efeitos adversos
11.
Eur Rev Med Pharmacol Sci ; 20(15): 3262-5, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27467002

RESUMO

The newborn digestive tract is rapidly colonized right after birth. The type of feeding could significantly influence this colonization process. Infant formulas like inulin try to mimic the bifidogenic effects of human milk by addition of prebiotics. Moreover, studies in the recent past have evidenced important effects of inulin during early infant life. The present review article will highlight recent updates about the use of inulin in the pediatric clinical setting.


Assuntos
Fórmulas Infantis , Inulina/fisiologia , Prebióticos , Alimento Funcional , Trato Gastrointestinal/efeitos dos fármacos , Humanos , Recém-Nascido , Oligossacarídeos
12.
Nanoscale ; 8(11): 5842-6, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26932823

RESUMO

We report a DNA origami-facilitated single-molecule platform that exploits atomic force microscopy to study DNA replication. We imaged several functional activities of the Klenow fragment of E. coli DNA polymerase I (KF) including binding, moving, and dissociation from the template DNA. Upon completion of these actions, a double-stranded DNA molecule was formed. Furthermore, the direction of KF activities was captured and then confirmed by shifting the KF binding sites on the template DNA.


Assuntos
DNA Polimerase I/química , DNA de Cadeia Simples/química , DNA/química , Escherichia coli/enzimologia , Transferência Ressonante de Energia de Fluorescência , Microscopia de Força Atômica , Sítios de Ligação , Carbocianinas/química , Replicação do DNA , Nanopartículas/química , Nanotecnologia
13.
Nanoscale ; 7(37): 15070-4, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26348717

RESUMO

We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca(2+) influx, and the influx of Ca(2+) is through ATP-activated channels instead of the voltage-gated Ca(2+) channel (VGC).


Assuntos
Técnicas Biossensoriais/métodos , Dopamina/análise , Nanopartículas Metálicas/química , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Dopamina/metabolismo , Ouro/química , Limite de Detecção , Microscopia/métodos , Imagem Óptica/métodos , Células PC12 , Ratos
14.
Case Rep Orthop ; 2014: 645927, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25276454

RESUMO

Extra-articular femoral deformity in total knee arthroplasty (TKA) is realigned by either intra-articular correction or extra-articular osteotomy. The more distant the deformity is away from knee joint, the more likely it is corrected by the former method. No report described the use of antegrade cephalomedullary femoral nail to fix the osteotomy followed by computer-assisted navigation TKA. This report described the unusual use of this method to manage a 64-year-old man with femoral subtrochanteric fracture malunion and osteoarthritis of knee. He demonstrated a satisfactory functional outcome and good lower limb alignment.

15.
Cell Death Dis ; 4: e876, 2013 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-24157870

RESUMO

Temozolomide (TMZ) is an alkylating agent currently used as first-line therapy for gliomas treatment due to its DNA-damaging effect. However, drug resistance occurs, preventing multi-cycle use of this chemotherapeutic agent. One of the major mechanisms of cancer drug resistance is enhanced activity of a DNA repair enzyme, O(6)-methylguanine-DNA-methyltransferase (MGMT), which counteracts chemotherapy-induced DNA alkylation and is a key component of chemoresistance. MGMT repairs TMZ-induced DNA lesions, O(6)-meG, by transferring the alkyl group from guanine to a cysteine residue. This review provides an overview of recent advances in the field, with particular emphasis on the inhibitors of MGMT and underlying mechanisms. Literature search was performed through PubMed and all relevant articles were reviewed, with particular attention to MGMT, its role in TMZ-resistant gliomas, effects of MGMT inhibitors and the underlying mechanisms. Several strategies are currently being pursued to improve the therapeutic efficacy of TMZ via inhibition of MGMT to reduce chemoresistance and improve overall survival. MGMT may be a promising target for the treatment of TMZ-resistant gliomas.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos , Glioma/tratamento farmacológico , Terapia de Alvo Molecular , O(6)-Metilguanina-DNA Metiltransferase/antagonistas & inibidores , Animais , Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/genética , Dacarbazina/química , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glioma/enzimologia , Glioma/genética , Humanos , O(6)-Metilguanina-DNA Metiltransferase/genética , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Temozolomida
16.
Int J Androl ; 34(4): 352-62, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20633196

RESUMO

Specialized junctions, which occur at sites of Sertoli-Sertoli and Sertoli-germ cell contact of seminiferous epithelium, play pivotal roles in spermatogenesis. Slight increase in scrotal temperature can induce oligospermia or azoospermia via increasing germ cell apoptosis. In this study, we demonstrated that the expression of tight junction (TJ) components, such as occludin, claudin-3 and zonula occludens-1 (ZO-1), was reduced 24-48h after a single mild scrotal heat exposure (43°C for 30min), whereas mRNA levels of claudin-11 were increased. Moreover, the protein localization of occludin and ZO-1 was lost from the blood-testis barrier (BTB) site, whereas claudin-11 immunostaining became diffuse and cytoplasmic 2days following heat exposure. Electron microscopic analysis showed that 2days after the heat treatment, the intercellular space between the two adjacent Sertoli cells was expanded, coupled with defragmentation of actin bundles and the endoplasmic reticulum. In addition, the TJ permeability increased significantly 2days after the heat exposure and recovered approximately 10days later. Heat-induced reversible BTB disruption was associated with a transient induction of transforming growth factor (TGF)-ß2, -3 and p38 mitogen-activated protein kinase activation. However, the TGF-ß antagonist only partially prevented the heat-induced BTB disruption. In conclusion, the expression of TJ-associated molecules and BTB were reversibly perturbed after mild testicular hyperthermia, and the induction of TGF-ß expression may be partially involved in heat-induced BTB damage.


Assuntos
Temperatura Alta , Escroto/fisiologia , Junções Íntimas/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Animais , Sequência de Bases , Western Blotting , Primers do DNA , Fertilidade , Masculino , Camundongos , Camundongos Endogâmicos ICR , Microscopia Eletrônica , Microscopia de Fluorescência , Reação em Cadeia da Polimerase , Escroto/ultraestrutura
17.
AJNR Am J Neuroradiol ; 30(5): 1041-5, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19246523

RESUMO

BACKGROUND AND PURPOSE: The carotid siphon is a natural barrier to intracranial interventions. Our aim was to make a model of the human intracranial internal carotid artery (ICA) and to test the navigability of covered stents for intracranial applications. MATERIALS AND METHODS: A digital tube was made on the basis of raw MR images of the human ICA. It was transferred into 10 physical models and then coated with silicone by using a 3D rapid prototyping (RP) machine. Ten dogs then underwent surgery. Their common carotid arteries (CCAs) were exposed, cut, and passed through 1 of the tubes. Finally, the vascular models were made by reanastomosis of their CCAs. Eight expended polytetrafluoroethylene (e-PTFE) covered stents (two 3.5 x 16 mm, two 3.5 x 13 mm, two 3.5 x 10 mm, and two 3.5 x 7 mm) were implanted 1 week later. Two dogs remained as controls. The performance of the device was evaluated by angiography and histopathologic examination. RESULTS: Ten animal models were successfully constructed. There was no vascular spasm or thrombosis when assessed by angiography. Destruction of the tunica intima and media was found in the 3.5 x 16 mm stent group. Destruction of the endothelium was found in the 3.5 x 13 mm stent group, and only flattening of the endothelium was found in the 3.5 x 10 mm and 3.5 x 7 mm stent groups. CONCLUSIONS: The experimental model was thought to simulate adequately the geometry of the human ICA and, thus, would be an effective tool for the research and testing of neurovascular devices. The length of the stent is 1 factor influencing the navigability in tortuous vessels.


Assuntos
Biomimética/instrumentação , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/cirurgia , Stents Farmacológicos , Modelos Biológicos , Animais , Cães , Humanos , Radiografia , Resultado do Tratamento
18.
Biosens Bioelectron ; 22(9-10): 2351-5, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16982184

RESUMO

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).


Assuntos
Nanopartículas , Nanotecnologia , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Silício
19.
Toxicol In Vitro ; 16(1): 41-6, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11812638

RESUMO

The biological activities of fullerenes have attracted extensive attention in recent years. The aim of this paper is to study the relation of the photo-induced cytotoxicity of fullerene derivatives to their chemical structures as well as the possible cellular mechanism involved in the photocytotoxicity. Three C(60) derivatives with two to four malonic acid groups (DMA C(60), TMA C(60) and QMA C(60)) were prepared and the cytotoxicity of these compounds against HeLa cells was determined by MTT. Cell cycle was measured by flow cytometry. The results showed that the cytotoxicity of the malonic acid C(60) derivatives was irradiation- and dose-dependent. The sequence of their photo-induced growth inhibition was DMA C(60)>TMA C(60)>QMA C(60). Hydroxyl radical quencher mannitol (10mM) was not able to prevent cells from the damage induced by irradiated DMA C(60). DMA C(60), together with irradiation, was found to have an ability of inducing a decrease in the number of G(1) cells from 63 to 42% and a rise in that of G(2)+M cells from 6 to 26%. These data indicated that the number of malonic acid molecules added to C(60) played an important role in the phototoxicity, and the blockage of cell cycle might be a mechanism of this activity.


Assuntos
Carbono/toxicidade , Fulerenos , Células HeLa/efeitos dos fármacos , Células HeLa/efeitos da radiação , Malonatos/toxicidade , Carbono/química , Ciclo Celular , Divisão Celular/efeitos dos fármacos , Divisão Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Citometria de Fluxo , Humanos , Luz , Malonatos/química , Manitol/farmacologia , Relação Estrutura-Atividade , Sais de Tetrazólio/metabolismo , Tiazóis/metabolismo
20.
Appl Opt ; 40(18): 3124-31, 2001 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-18357333

RESUMO

Laser ablation is widely used in micromachining, manufacturing, thin-film formation, and bioengineering applications. During laser ablation the removal of material and quality of the features depend strongly on the optical breakdown region induced by the laser irradiance. The recent advent of amplified ultrafast lasers with pulse durations of less than 1 ps has generated considerable interest because of the ability of the lasers to process virtually all materials with high precision and minimal thermal damage. With ultrashort pulse widths, however, traditional breakdown models no longer accurately capture the laser-material interaction that leads to breakdown. A femtosecond breakdown model for dielectric solids and liquids is presented that characterizes the pulse behavior and predicts the time- and position-dependent breakdown region. The model includes the pulse propagation and small spatial extent of ultrashort laser pulses. Model results are presented and compared with classical breakdown models for 1-ns, 1-ps, and 150-fs pulses. The results show that the revised model is able to model breakdown accurately in the focal region for pulse durations of less than 10 ps. The model can also be of use in estimating the time- and position-resolved electron density in the interaction volume, the breakdown threshold of the material, shielding effects, and temperature distributions during ultrafast processing.

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