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1.
J Eur Acad Dermatol Venereol ; 34(3): 624-632, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31494973

RESUMO

BACKGROUND: Recent evidence suggests melasma to be a photoaging disorder. Triple combination creams (TCC: fluocinolone acetonide 0.01%, hydroquinone 4% and tretinoin 0.05%) remain the gold standard treatment. Picosecond alexandrite laser treatment using a diffractive lens array (DLA) has been identified to be effective for improving photoaging conditions. OBJECTIVE: We aimed to compare the efficacy and tolerance of the picosecond alexandrite laser with those of DLA and TCC in female Asian patients with melasma. METHODS: Twenty-nine patients were randomly assigned to group A1 (3 laser sessions at 4-week intervals), A2 (5 laser sessions at 4-week intervals) or B (TCC daily for at least 8 weeks and then tapered until the final evaluation). The Melasma Area, Severity Index (MASI) score and VISIA were assessed at baseline, week 12 and week 20. By week 20, the follow-up periods for groups A1 and A2 were 3 months and 1 month, respectively. RESULTS: Nine, 11 and 6 participants in groups A1, A2 and B completed the study, respectively. MASI scores were significantly improved in all 3 groups at weeks 12 and 20. In groups A1, A2 and B, the improvement rates at week 20 were 53%, 38% and 50%, respectively. VISIA® analysis additionally revealed a significant improvement in spots, porphyria, pores and brown spots after 3 laser sessions (P < 0.05). Group A2 showed greater improvements than group A1 in terms of spots, wrinkles and pores; however, only red areas were significantly different (P < 0.001). All side-effects in the 3 groups were transient and gradually subsided after 1-3 months. CONCLUSION: Picosecond alexandrite laser treatment using DLA showed comparable efficacy with TCC for the treatment of melasma. Improvements in texture, spots, wrinkles and pores were observed in the laser groups. Patients with melasma lesions that exhibit telangiectasia may benefit from additional laser treatment sessions.


Assuntos
Fluocinolona Acetonida/administração & dosagem , Hidroquinonas/administração & dosagem , Lasers de Estado Sólido/uso terapêutico , Melanose/tratamento farmacológico , Melanose/cirurgia , Tretinoína/administração & dosagem , Adulto , Povo Asiático , Terapia Combinada , Combinação de Medicamentos , Feminino , Humanos , Pessoa de Meia-Idade , Pomadas , Estudos Prospectivos , Método Simples-Cego , Resultado do Tratamento
3.
Tissue Antigens ; 80(3): 224-30, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22731780

RESUMO

Graves disease (GD) is an autoimmune thyroid disease with a female preponderance and a wide range of ages at onset, and human leukocyte antigen (HLA) gene plays a primary role in the susceptibility to GD. We aim to investigate the associations between HLA-DRB1 alleles and Taiwanese children with GD by both case-control and family-based studies. A total of 241 unrelated children with GD, 539 healthy controls, 115 trios of affected patients and their parents, and 121 trios of unaffected siblings and their parents were recruited. HLA-DRB1 genotyping was performed by polymerase chain reaction and sequence-based typing assays. We found that DRB1*09:01 (OR=2.60, 95% CI 2.02-3.35, Pc=6.55×10(-13)) was associated with GD risk, while DRB1*12:02 (OR=0.32, 95% CI 0.20-0.53, Pc=4.55×10(-5)) was protective against GD. Transmission/disequilibrium test further confirmed an overtransmission of the DRB1*09:01 (OR 3.37, 95% CI 2.13-6.22, Pc=1.0×10(-5)) and an undertransmission of the DRB1*12:02 (OR 0.21, 95% CI 0.05-0.42, Pc=1.7×10(-3)). The findings were similar in females when stratified by gender. In conclusion, our results clearly identify that HLA-DRB1*09:01 confers susceptibility to GD and DRB1*12:02 exerts protection against GD development in Taiwanese children.


Assuntos
Predisposição Genética para Doença , Doença de Graves/genética , Doença de Graves/imunologia , Cadeias HLA-DRB1/genética , Adolescente , Alelos , Aminoácidos/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Família , Feminino , Frequência do Gene/genética , Humanos , Desequilíbrio de Ligação/genética , Masculino , Irmãos , Taiwan/etnologia , Adulto Jovem
4.
J Appl Microbiol ; 112(3): 551-60, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22151398

RESUMO

AIMS: Zero-valent iron (ZVI) filters may provide an efficient method to mitigate the contamination of produce crops through irrigation water. METHODS: A field-scale system was utilized to evaluate the effectiveness of a biosand filter (S), a biosand filter with ZVI incorporated (ZVI) and a control (C, no treatment) in decontaminating irrigation water. An inoculum of c.8·5log CFU100ml(-1) of Escherichia coli O157:H12 was introduced to all three column treatments in 20-l doses. Filtered waters were subsequently overhead irrigated to 'Tyee' spinach plants. Water, spinach plant and soil samples were obtained on days 0, 1, 4, 6, 8, 10, 13 and 15 and analysed for E. coli O157:H12 populations. RESULTS: ZVI filters inactivated c.6logCFU100ml(-1) E. coli O157:H12 during filtration on day 0, significantly (P<0·05) more than S filter (0·49CFU100ml(-1)) when compared to control on day 0 (8·3log CFU100ml(-1)). On day 0, spinach plants irrigated with ZVI-filtered water had significantly lower E. coli O157 counts (0·13logCFUg(-1)) than spinach irrigated with either S-filtered (4·37logCFUg(-1)) or control (5·23logCFUg(-1)) water. Soils irrigated with ZVI-filtered water contained E. coli O157:H12 populations below the detection limit (2logCFUg(-1)), while those irrigated with S-filtered water (3·56logCFUg(-1)) were significantly lower than those irrigated with control (4·64logCFUg(-1)). CONCLUSIONS: ZVI biosand filters were more effective in reducing E. coli O157:H12 populations in irrigation water than sand filters. SIGNIFICANCE AND IMPACT OF THE STUDY: Zero-valent ion treatment may be a cost-effective mitigation step to help small farmers reduce risk of foodborne E. coli infections associated with contamination of leafy greens.


Assuntos
Agricultura/métodos , Escherichia coli O157/isolamento & purificação , Contaminação de Alimentos/prevenção & controle , Ferro/química , Spinacia oleracea/microbiologia , Irrigação Agrícola , Contagem de Colônia Microbiana , Escherichia coli O157/crescimento & desenvolvimento , Filtração , Microbiologia de Alimentos , Folhas de Planta/microbiologia , Microbiologia do Solo , Microbiologia da Água
5.
Sci Adv ; 6(37)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32917695

RESUMO

Embryonic diapause is a maternally controlled phenomenon. The molecule controlling the onset of the phenomenon is unknown. We demonstrated that overexpression of microRNA let-7a or incubation with let-7g-enriched extracellular vesicles from endometrial epithelial cells prolonged the in vitro survival of mouse blastocysts, which developed into live pups after having been transferred to foster mothers. Similar to in vivo dormant blastocysts, let-7-induced dormant blastocysts exhibited low level of proliferation, apoptosis, and nutrient metabolism. Let-7 suppressed c-myc/mTORC1 and mTORC2 signaling to induce embryonic diapause. It also inhibited ODC1 expression reducing biosynthesis of polyamines, which are known to reactivate dormant embryos. Furthermore, the overexpression of let-7 blocked trophoblast differentiation and implantation potential of human embryo surrogates, and prolonged survival of human blastocysts in vitro, supporting the idea that embryonic diapause was an evolutionary conserved phenomenon. In conclusion, let-7 is the main factor inducing embryonic diapause.


Assuntos
Diapausa , Vesículas Extracelulares , MicroRNAs , Animais , Blastocisto/fisiologia , Implantação do Embrião/genética , Desenvolvimento Embrionário/genética , Endométrio/metabolismo , Vesículas Extracelulares/metabolismo , Feminino , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo
6.
Int J Androl ; 32(6): 687-94, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19076257

RESUMO

Leptin is a polypeptide hormone with important roles in reproduction. It has been detected in human seminal plasma as well as on human ejaculated spermatozoa. This study aimed at studying the possible role of leptin in regulating human sperm functions. Immunofluorescent staining was used to study the expression of leptin and its receptor. The correlation between the concentration of leptin and soluble leptin receptor (ObRs) in seminal plasma as measured by enzyme-linked immunosorbant assay and sperm motility parameters measured by computer-assisted sperm analysis (CASA) was determined. The effects of recombinant leptin on human sperm motility, capacitation and acrosome reaction as measured by chlortetracycline staining were also studied. Leptin immunoreactivity was demonstrated at the equatorial and neck regions of human spermatozoa, whereas that of ObRs was shown up on the tail. After Percoll separation, spermatozoa with high density had more intense leptin immunoreactivity compared with those with low density. No significant correlation was found between seminal plasma concentration of leptin/ObRs and sperm motility parameters. After incubation with recombinant human leptin for either 3 h or overnight, there was no change in all the CASA motility parameters determined and percentages of capacitated and acrosome-reacted spermatozoa. We concluded that leptin does not have a significant effect on motility and capacitation/acrosome reaction in human ejaculated mature spermatozoa. Its role in male reproduction is yet to be determined.


Assuntos
Reação Acrossômica/efeitos dos fármacos , Leptina/metabolismo , Leptina/farmacologia , Capacitação Espermática/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Reação Acrossômica/fisiologia , Contagem de Células , Clortetraciclina/metabolismo , Clortetraciclina/farmacologia , Humanos , Masculino , Sêmen/metabolismo , Motilidade dos Espermatozoides/fisiologia , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Espermatozoides/fisiologia
8.
Water Sci Technol ; 54(10): 47-53, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17165447

RESUMO

The use of zero-valent iron for treating wastewaters containing RDX and perchlorate from an army ammunition plant (AAP) in the USA at elevated temperatures and moderately elevated temperature with chemical addition was evaluated through batch and column experiments. RDX in the wastewater was completely removed in an iron column after 6.4 minutes. Increasing the temperature to 75 degrees C decreased the required retention time to 2.1 minutes for complete RDX removal. Perchlorate in the wastewater was completely removed by iron at an elevated temperature of 150 degrees C in batch reactors in 6 hours without pH control. Significant reduction of perchlorate by zero-valent iron was also achieved at a more moderate temperature (75 degrees C) through use of a 0.2 M acetate buffer. Based on the evaluation results, we propose two innovative processes for treating RDX-containing and perchlorate-containing wastewaters: a temperature and pressure-controlled batch iron reactor and subsequent oxidation by existing industrial wastewater treatment plant; and reduction by consecutive iron columns with heating and acid addition capabilities and subsequent oxidation.


Assuntos
Substâncias Explosivas/metabolismo , Resíduos Industriais , Ferro/química , Percloratos/metabolismo , Triazinas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Substâncias Explosivas/análise , Substâncias Explosivas/química , Oxirredução , Percloratos/análise , Percloratos/química , Temperatura , Triazinas/análise , Triazinas/química , Estados Unidos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
9.
J Infect ; 46(4): 238-43, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12799149

RESUMO

OBJECTIVES: A major outbreak of enterovirus 71 (EV71) in Taiwan in 1998 caused many severe cases and 78 deaths. Our purpose was to find reliable markers and early indicators of fatal EV71 central nervous system (CNS) infection. METHODS: From June 2000 to November 2001, 21 patients with hand foot mouth disease or herpangina with CNS infection were admitted to Kaohsiung Veterans General Hospital. All 21 had culture-confirmed EV71 infection or were EV71 IgM positive. Patients were divided into two groups: group I included the five fatalities at our institution and group II, the 16 surviving patients. RESULTS: Of the 21 infants and children with EV71 infection with CNS involvement, MR imaging studies were completed on 17, and 15 showed hyperintensity in the posterior portions of brain stem. All patients received intravenous immunoglobulin (IVIG) 1 g/day for two days and supportive care. Five patients rapidly deteriorated owing to irreversible hypotension and died. The other 16 patients recovered completely without sequel. In group I patients, the decrease of cardiac ejection function is significant and laboratory findings showed lower platelet count (P=0.0192). The mean of initial cTnI level for groups I and II was 10.6+/-11.6 and 0.48+/-0.55 ng/dl, respectively, higher in group I than in II (P=0.0019). CONCLUSION: We hypothesized that like patients with severe burns, those with severe EV-71 CNS meningoencephalitis have varying degrees of non-ischemic cardiac injury, manifesting as leakage of cTnI from myocytes into the circulation. EV-71 CNS meningoencephalitis likely to die with an early myocardial involvement evidenced by reduced ejection fraction and release of cTnI. We conclude that fatal EV71 CNS infection quickly leads to death due to severe encephalopathy associated with cardiomyopathy.


Assuntos
Viroses do Sistema Nervoso Central/etiologia , Infecções por Enterovirus/complicações , Cardiopatias/etiologia , Troponina I/sangue , Biomarcadores/sangue , Viroses do Sistema Nervoso Central/mortalidade , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Surtos de Doenças , Infecções por Enterovirus/epidemiologia , Feminino , Cardiopatias/epidemiologia , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Fatores de Risco , Estatísticas não Paramétricas , Taiwan/epidemiologia
10.
Water Res ; 35(13): 3077-84, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11487103

RESUMO

Trichloroethene (TCE) transformation and the product distribution in an aqueous medium containing zero-valent iron (Fe(0)) was investigated in the presence of an anaerobic mixed culture to assess the potential role of microorganisms in permeable iron barriers. The presence of the culture increased the rate of TCE disappearance and changed the product distribution. Rapid formation and degradation of cis-dichloroethene (cis-DCE) was observed in reactors containing cells plus Fe(0) or H2 as a bulk reducing agent. High levels of vinyl chloride (VC) were formed and very similar profiles were obtained in the Fe(0) plus cell and H2 plus cell reactors, but not in Fe(0)-only reactors. The similar trends observed in Fe(0)-cell and H2-cell reactors suggest that most cis-DCE and VC in the Fe(0)-cell reactors were produced and transformed biologically rather than abiotically. Accumulation of methane in the Fe(0)-cell system indicates that hydrogen gas generated during anaerobic iron corrosion could support a methanogenic culture. Digital confocal images showed that the microorganisms were able to colonize the iron surface. The results suggest that potential development of dechlorinating populations in Fe(0) barriers may alter the TCE reduction pathway and produce VC, which would have significant impact on the performance of Fe(0) barriers.


Assuntos
Bactérias Anaeróbias/metabolismo , Reatores Biológicos , Hidrocarbonetos Clorados/metabolismo , Ferro/metabolismo , Tricloroetileno/metabolismo , Biodegradação Ambiental , Meios de Cultura , Etano/metabolismo , Hidrocarbonetos Clorados/química , Hidrogênio/metabolismo , Metano/metabolismo , Oxirredução , Fatores de Tempo , Tricloroetileno/química , Cloreto de Vinil/metabolismo
11.
Water Res ; 35(18): 4370-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11763039

RESUMO

Dibenzothiophene is decomposed rapidly by sonication in aqueous solution. Decomposition of dibenzothiophene follows a first-order reaction kinetics. The rate constant was found to increase with increasing ultrasonic energy intensity, temperature, and pH and decrease with increasing initial dibenzothiophene concentration. The activation energy was 12.6 kJ mol in the temperature range of 15-50 degrees C, suggesting a diffusion-controlled reaction. Hydroxydibenzothiophenes and dihydroxydibenzothiophenes were identified as reaction intermediates. It is proposed that dibenzothiophene is oxidized by OH radical to hydroxy-dibenzothiophenes and then to dihydroxy-dibenzothiophenes. Kinetic analysis suggests that approximately 72% of the dibcnzothiophene decomposition occurred via OH radical addition. A pathway and a kinetic model for the sonochemical decomposition of dibenzothiophene in aqueous solution are proposed.


Assuntos
Sonicação , Tiofenos/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Radical Hidroxila , Cinética
12.
J Formos Med Assoc ; 95(10): 793-7, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8961678

RESUMO

A 34-month-old girl presented with a clinical picture of Kenny syndrome. The clinical manisfestations included growth retardation, persistent open anterior fontanelle, prominent forehead, mid-facial dysplasia, hypocalcemic tetany and characteristic radiologic skeletal abnormalities. Serum levels of immunoreactive parathyroid hormone (PTH) remained inappropriately low during hypocalcemic episodes in the neonatal period; indicating that hypocalcemia was a consequence of the hypoparathyroid state. This is the first reported case of Kenny syndrome in Taiwan. The literature on the pathogenesis, etiology and genetic basis of this disorder is reviewed in this paper.


Assuntos
Anormalidades Múltiplas/etiologia , Osso e Ossos/anormalidades , Anormalidades do Olho/etiologia , Transtornos do Crescimento/etiologia , Hipocalcemia/etiologia , Anormalidades Múltiplas/genética , Pré-Escolar , Feminino , Humanos , Síndrome
13.
J Formos Med Assoc ; 91(12): 1162-5, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1363637

RESUMO

The major concern of the national population policy in Taiwan in recent years has been to lower the incidence of hereditary diseases and mental retardation in the general population. It has been estimated that there are around 10,000 mentally retarded school children in Taiwan. If effective chromosomal screening can be extended to these children, some of the family members who are carriers of balanced chromosomal rearrangements may benefit from follow-up studies and genetic counseling. The present report is the result of a pilot study conducted from 1988 to 1991 to explore the possibility of chromosomal screening of mentally retarded school children in Taipei. A total of 871 blood samples were collected from 1,147 children registered in 46 schools or residing in homes for the retarded. Chromosomal analysis was successfully accomplished on 674 out of 871 blood samples. The following chromosomal abnormalities were observed: 28 Down's syndrome, four Klinefelter syndrome, one XYY, one triple X, 11 translocations, seven inversions, four mosaics, three duplications, one deletion and one with an extra marker chromosome. After follow-up cytogenetic analyses of 13 families with probands with structural chromosomal anomalies, three of these families were shown to have one or two carriers of balanced translocated chromosomes. It seems that the present screening system would not be practical or cost-effective if it were applied island-wide in the future.


Assuntos
Aberrações Cromossômicas , Deficiência Intelectual/genética , Adolescente , Criança , Feminino , Seguimentos , Aconselhamento Genético , Humanos , Masculino , Aberrações dos Cromossomos Sexuais/genética
14.
J Formos Med Assoc ; 97(3): 186-90, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9549269

RESUMO

The mucopolysaccharidoses are a group of inherited disorders of lysosomal storage of glycosaminoglycans. Among them, mucopolysaccharidosis (MPS) type II (Hunter's syndrome), caused by a deficiency in iduronate sulfatase, is the only one inherited in an X-linked recessive manner. We describe 12 Hunter's syndrome patients and seven carriers, with precise analysis of glycosaminoglycan content in urine and iduronate sulfatase activity in cultured fibroblasts and plasma. Their ages at the time of diagnosis ranged from 1 year 10 months to 11 years (mean 4.3 yr). The delay in diagnosis was from 1 month to 5 years (mean 2.1 yr) after the initial presentation. The most frequent initial complaints of the patients were delayed developmental milestones (75%) and speech (67%), although all patients were found to have coarsening of facial features at diagnosis. The difficulties in disease recognition allowed disease recurrence in four of the 11 families. Prompt clinical suspicion and referral will be important in genetic counseling for MPS type II and its management, if definitive therapy becomes available.


Assuntos
Mucopolissacaridose II/complicações , Adolescente , Adulto , Transplante de Medula Óssea , Criança , Pré-Escolar , Feminino , Glicosaminoglicanos/urina , Humanos , Iduronato Sulfatase/genética , Iduronato Sulfatase/metabolismo , Lactente , Masculino , Mucopolissacaridose II/metabolismo , Mucopolissacaridose II/terapia
15.
Water Sci Technol ; 50(4): 115-20, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15484750

RESUMO

An analytical method involving solid-phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was applied to analyze biosolids odors. A selective ion monitoring (SIM)-based MS method was developed, using SPME injections of odorant standards under the full-scan mode to select the quantification and confirmation ions for each odorant. The odorants analyzed in this study include: dimethylsulfide, dimethyldisulfide, methyl mercaptan, hydrogen sulfide, carbon disulfide, trimethylamine and dimethylamine. We have used this method to quantify parts-per-billion levels of odorant vapors produced during anaerobic incubation of digested wastewater sludge. Important considerations for expedient and accurate calibration under static and dynamic flow conditions are discussed. The SPME-GC-MS method may give a positive intercept in the calibration curve, especially under static sampling conditions, which sets a practical detection limit for odor analysis.


Assuntos
Compostos de Nitrogênio/análise , Odorantes/análise , Compostos de Enxofre/análise , Técnicas de Química Analítica/métodos , Cromatografia Gasosa-Espectrometria de Massas , Sensibilidade e Especificidade , Eliminação de Resíduos Líquidos
16.
Water Sci Technol ; 47(10): 93-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12862222

RESUMO

Munitions manufacturing wastewater is commonly treated by adsorption to activated carbon. We are proposing a new munitions manufacturing wastewater treatment system consisting of a reductive pre-treatment process and subsequent Fenton's oxidation to mineralize energetic compounds such as TNT and RDX. The pre-treatment involves reduction of electron-withdrawing nitro groups of TNT and RDX with elemental iron. The iron-treated explosives are then oxidized by Fenton's reagent through the addition of H2O2. The objective of this work is to investigate the feasibility of using elemental iron to convert TNT and RDX to reduction products which may be more oxidizable in subsequent Fenton's oxidation. Results of batch reduction experiments with elemental iron showed complete removal of TNT and RDX and formation of the reduction products within 60 minutes. Results of column experiments showed a rapid and complete removal of TNTand RDX within 9.7 minutes retention time. Fitting observed effluent concentrations to a one-dimensional advection-dispersion equation, we were able to predict the concentration profiles of TNT and RDX in the iron column and calculate the iron column length required for the desired removal. The results of Fenton's oxidation experiments showed that iron pre-treatment enhanced both the rate and extent of TNT and RDX mineralization by Fenton's oxidation.


Assuntos
Ferro/química , Rodenticidas/química , Triazinas/química , Trinitrotolueno/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Adsorção , Carbono/química , Oxirredução
17.
Water Sci Technol ; 49(5-6): 129-36, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15137416

RESUMO

Pink water, explosive-laden wastewater produced in army ammunition plants is often treated using expensive and non-destructive granular activated carbon (GAC) adsorption. This paper compares GAC adsorption and two alternative treatment technologies, anaerobic GAC fluidized bed reactor and zero-valent iron-Fenton process. The bench-scale demonstration of the zero-valent iron-Fenton process with real pink water is reported. The features of three technologies are compared and their advantages and drawbacks are discussed.


Assuntos
Bactérias Anaeróbias/fisiologia , Reatores Biológicos , Carbono/química , Peróxido de Hidrogênio/química , Ferro/química , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/isolamento & purificação , Adsorção , Resíduos Perigosos , Oxirredução
18.
Kaohsiung J Med Sci ; 12(9): 522-8, 1996 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-8819355

RESUMO

The linear attenuation coefficient (mu) is an important coefficient in the study of diagnostic radiology. The mu values of dentin and enamel were rarely reported because they are thin and tightly connected to each other and are difficult to measure by thermoluminescent dosimeters or ion chambers. In this work, we used film densitometry to measure the radiation dose before and after they transmitted the 2 mm thickness tooth slice and used this data to calculate the mu values of enamel and dentin. The results show that the mu values of enamel at 70, 80, 90kVp are 2.97 +/- 0.71, 2.85 +/- 0.07, 2.70 +/- 0.16 cm-1, respectively. The mu values of dentin at 70, 80, 90kVp are 2.12 +/- 0.92, 1.81 +/- 0.23, 1.89 +/- 0.42 cm-1, respectively. The mu values may be affected by the equivalent energy of an x-ray generator operated under different kVp conditions and also by the density and calcification degree of the enamel and dentin. Nevertheless, the results obtained in this study still can severe as a reference for researchers.


Assuntos
Radiografia Dentária , Esmalte Dentário , Dentina , Humanos
19.
Kaohsiung J Med Sci ; 13(10): 631-4, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9385780

RESUMO

The main purpose of this study is to find out the degree of attenuation when the x-ray entrances the skin and reaches the film at the bone area near the mandibular premolar root apex. In this study we used thermaluminescent dosimeters (TLDs) to measure the entrance dose and exit dose directly at the area of interest and calculated the penetration value P. We also simulated the attenuation process and calculated the P value in similar conditions. The results indicate that the mean P value of direct measurement from patient is 0.071 +/- 0.018 (60kVp, HVL = 1.5mm Al), while that for theoretical calculation is 0.06458 at 27keV. We concluded that P value of direct measurement can match with the theoretical value and further studies in jaw bone density and other related portions is worthwhile.


Assuntos
Processo Alveolar/efeitos da radiação , Mandíbula/efeitos da radiação , Músculos/efeitos da radiação , Doses de Radiação , Feminino , Humanos , Masculino
20.
Andrology ; 2(6): 868-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25168311

RESUMO

Ulipristal acetate (UPA) and mifepristone are currently well-established agents for emergency contraception. Both drugs are selective progestogen receptor modulators which have been shown to have better efficacy than the widely used levonorgestrel in prevention of pregnancy. However, there is only limited information on the action of UPA on sperm function. The present study compared the in vitro biological effects of mifepristone and UPA on human sperm functions. Spermatozoa from semen samples with normal semen parameters were isolated. Capacitated spermatozoa were pre-incubated with 0.04, 0.4, 4 and 40 µM mifepristone or UPA for 1 h. Sperm motility, viability, DNA integrity, capacitation, spontaneous acrosome reaction, spontaneous hyperactivation, zona pellucida (ZP) binding capability and intracellular calcium concentration ([Ca(2+)]i) were determined. The effects of mifepristone and UPA on progesterone-induced acrosome reaction, hyperactivation and [Ca(2+)]i were also studied. Our results showed that mifepristone and UPA dose-dependently suppressed progesterone-induced acrosome reaction, hyperactivation and [Ca(2+)]i at concentrations ≥0.4 µM in human spermatozoa. Both compounds did not affect sperm motility, viability, DNA integrity, capacitation, spontaneous acrosome reaction, spontaneous hyperactivation, ZP binding capability and [Ca(2+)]i. This study demonstrated that UPA and mifepristone modulate human sperm functions by acting as progesterone antagonists. The results enable us to gain a better understanding of the mechanisms by which mifepristone and UPA work for emergency contraception, and provide a scientific basis for their clinical application.


Assuntos
Mifepristona/farmacologia , Norpregnadienos/farmacologia , Espermatozoides/efeitos dos fármacos , Reação Acrossômica , Cálcio/metabolismo , Humanos , Técnicas In Vitro , Masculino , Capacitação Espermática , Motilidade dos Espermatozoides
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