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1.
Zhonghua Er Ke Za Zhi ; 59(4): 311-315, 2021 Apr 02.
Artigo em Chinês | MEDLINE | ID: mdl-33775051

RESUMO

Objective: To evaluate the efficacy and safety of eltrombopag for children with thrombocytopenia after hematopoietic stem cell transplantation (HSCT). Methods: Clinical data of 24 patients with thrombocytopenia after HSCT,who were treated with eltrombopag in the Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University from August 1, 2018 to April 1, 2019 were analyzed retrospectively. The response rate and adverse reactions of eltrombopag were evaluated. Patients were divided into groups by source of hematopoietic stem cells (umbilical cord blood group and peripheral stem cell group) and type of disease (malignant and non-malignant disease group) and the clinical outcomes between groups were compared. Rank Sum test was used for comparisons between groups. Results: Among 24 cases, 15 were males and 9 females, the age of starting eltrombopag was 7.7 (2.6-13.7) years, the time of eltrombopag treatment after HSCT was 27.5 (8.0-125.0) days, the time from treatment to complete response (CR) was 23.5 (6.0-83.0) days, with the treatment course 36.5 (8.0-90.0) days. The total dose of eltrombopag was 1 400(200-5 900) mg. Complete response rate was 92% (22/24),without eltrombopag related adverse reactions. Comparing with peripheral stem cell group (n=8), the course and total dose of eltrombopag in umbilical cord blood group (n=16) were significantly reduced(24.5 (8.0-81.0) vs. 65.5 (35.0-90.0) d, Z=-3.004, P=0.002; 900.0 (200.0-3 850.0) vs. 2 862.5 (1 175.0-5 900.0) mg, Z=-2.604, P=0.007), but no significant differences were found in the time from treatment to complete response, platelet count after 2 weeks of eltrombopag withdrawal or platelet count at the end point of follow-up (all P>0.05). Comparing malignant patients (n=12) and non-malignant patients (n=12), no significant differences were found in the time from treatment to complete response, course, total dose, platelet count after 2 weeks of eltrombopag withdrawal, and platelet count at the end point of follow-up in non-malignant patients (all P>0.05). Conclusion: Eltrombopag is safe and maybe effective for thrombocytopenia after HSCT, especially for umbilical cord blood transplantation.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Trombocitopenia , Adolescente , Benzoatos , Criança , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Hidrazinas/uso terapêutico , Masculino , Pirazóis , Estudos Retrospectivos , Trombocitopenia/tratamento farmacológico , Trombocitopenia/etiologia , Resultado do Tratamento
2.
Eur Rev Med Pharmacol Sci ; 24(22): 11594-11601, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33275226

RESUMO

OBJECTIVE: Many studies have revealed that long non-coding RNAs (lncRNAs) are related to various cancers, including colorectal cancer (CRC). This study aims to explore the biological function of lncRNA PSMA3-AS1 in CRC progression. MATERIALS AND METHODS: The expression levels of PSMA3-AS1 and miR-4429 were assessed by RT-qPCR. CRC progression was explored by cell viability, migration, and invasion using CCK-8 and transwell assays. The interaction between PSMA3-AS1 and miR-4429 was verified by bioinformatics analysis, Dual-Luciferase assay, and RIP assay. RESULTS: It was found that PSMA3-AS1 expression was increased and miR-4429 expression was decreased in CRC tissues and cells. In addition, PSMA3-AS1 interference markedly hindered the proliferation, migration, and invasion of CRC cells. MiR-4429 was a direct target of PSMA3-AS1, and the knockdown of PSMA3-AS1 significantly suppressed miR-4429 expression. The depletion of PSMA3-AS1 inhibited CRC progression, which was neutralized by miR-4429 inhibitor. CONCLUSIONS: PSMA3-AS1 accelerated CRC progression by regulating miR-4429 expression, which could be used as a potential therapeutic target for CRC patients.


Assuntos
Neoplasias Colorretais/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Movimento Celular , Sobrevivência Celular , Células Cultivadas , Neoplasias Colorretais/patologia , Humanos , MicroRNAs/genética , RNA Longo não Codificante/genética
3.
Water Res ; 176: 115754, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32247993

RESUMO

In this study, the mechanisms for solids breakthrough in upflow anaerobic sludge blanket (UASB) configured anaerobic membrane bioreactors (AnMBRs) have been described to establish design parameters to limit membrane fouling. As the sludge blanket develops, two periods can be identified: (i) an initial progressive enhancement in solids separation provided through sludge blanket clarification, via depth filtration, which sustains downstream membrane permeability; and (ii) sludge blanket destabilisation, which imposed solids breakthrough resulting in a loss in membrane permeability. The onset of sludge blanket destabilisation was identified earlier in the flocculent AnMBR, which was ascribed to an increased gas production, caused by hydrolysis within the sludge blanket at extended solids residence time. Whilst hydrolysis also induced higher gas productivity within the granular AnMBR, solids breakthrough was not evidently observed during this period, and was instead only observed as the sludge blanket approached the UASB overflow. However, solids breakthrough was observed earlier for both reactors when treating wastewater with lower temperatures. This was explained through characterisation of the settling velocity of discrete particles from the sludge blanket of both MBRs; solids washout was evidenced to be induced by the increase in fluid viscosity with a reduction in temperature, which lowered terminal particle settling velocity. Nevertheless, particle settling velocity was comparable for particles from both sludge blankets. We therefore propose that the enhanced stability imparted by the granular AnMBR is due to the higher inertial force of the dense granular sludge. From this study, we suggest that similarly low levels of membrane fouling can be achieved within flocculent AnMBR by managing solids retention time to constrain sludge bed height and excess hydrolysis, together with adopting an upflow velocity based on particle buoyancy at the lowest expected operating temperature.


Assuntos
Reatores Biológicos , Esgotos , Anaerobiose , Filtração , Eliminação de Resíduos Líquidos , Águas Residuárias
4.
Bioresour Technol ; 301: 122798, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31981907

RESUMO

The polyvinyl formal (PVFM) biocarrier addition in a membrane bioreactor (MBR) was evaluated at high and low carbon/nitrogen (C/N) ratio of 20.0 and 6.7. Results indicated that static biocarrier addition could enrich nitrification and denitrification bacteria, dominating by Tauera, Amaricoccus and Nitrosospira at the genus level and slightly improved the total nitrogen removal even at a low C/N ratio. The bulk sludge characteristics (such as bigger particle size, lower SMP, lower SMP P/C) were also significantly changed in the hybrid MBR (HMBR), leading to a more sustainable membrane operation. The biocarrier addition also reduced the relative abundance of Sphingobacterials_unclassified, Ohtaekwangia and Rhodocyclaceae_unclassified at the genus level, indicating less membrane fouling in the HMBR. Consequently, HMBR with static PVFM addition could partially overcome the drawback of low C/N ratio for total nitrogen removal and membrane fouling control, providing a more resilient MBR to the undesirable environment such as low C/N ratio.


Assuntos
Microbiota , Nitrogênio , Reatores Biológicos , Desnitrificação , Membranas Artificiais , Esgotos , Eliminação de Resíduos Líquidos
5.
J Hazard Mater ; 384: 121458, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31676166

RESUMO

Anode passivation is still a main challenge for the electrochemical generation of ferrate(VI, Fe(VI)), leading to the reduction of Fe(VI) production efficiency. In this study, cyclic voltammetry, scanning electronic microscopy, and electrochemical impedance spectroscopy were used to select better anode electrode configurations (iron wire, iron gauze, and iron coil). The results indicate that iron coil had the least degree of passivation. Different imposed current waveforms during the electrochemical generation of Fe(VI) were also investigated, and the iron coil imposed with square alternating current (AC) wave can mitigate the anode passivation, resulting in higher Fe(VI) production efficiency. The optimum conditions for the electrochemical generation of Fe(VI) were evaluated and the optimum temperature (40 ℃), current density (10 mA/cm2), AC cycle period (15 s) and electrolyte concentrations (14 M NaOH) were identified. As a result, 0.12 mol/L Fe(VI) concentration and over 50% of current efficiency can be achieved after 3 h electrolysis. The generated Fe(VI) solution was further applied to oxidize doxycycline(DOX) and sulfadiazine(SDZ) as typical antibiotics. Over 80% of DOX can be removed at a Fe(VI) to DOX molar ratio of 5:1 (pH = 4-9), whilst a higher Fe(VI) to SDZ molar ratio of 20:1 (pH = 7) was needed to obtain 75% SDZ removal.


Assuntos
Antibacterianos/química , Técnicas Eletroquímicas , Ferro/química , Poluentes Químicos da Água/química , Espectroscopia Dielétrica , Eletrodos , Microscopia Eletrônica de Varredura
7.
Artigo em Inglês | MEDLINE | ID: mdl-28393417

RESUMO

The prevention of chemotherapy-induced nausea and vomiting was one of the most challenging supportive care issues in oncology, especially to highly emetogenic chemotherapy (HEC). A total of 645 patients were randomized into fosaprepitant group (fosaprepitant/placebo 150 mg d1 in combination with granisetron and dexamethasone) or aprepitant group (aprepitant/placebo 125 mg d1; 80 mg d2-d3 plus granisetron and dexamethasone).The primary endpoint was the percentage of patients who had a complete response (CR) over the entire treatment course (0-120 hr, overall phase [OP]). It was assessed by using a non-inferiority model, with a non-inferiority margin of 10%. The difference of the CR rate was compared between two groups with chi-square analysis. Six hundred and twenty-six patients were included in the per protocol analysis. The percentage of patients with a CR in the fosaprepitant group was not inferior to that in the aprepitant group (90.85% versus 94.17%, p = .1302) during OP. Whether the cisplatin-based chemotherapy or not, the CR rate of the fosaprepitant group was not inferior to that of the aprepitant group. Both regimens were well tolerated. The most common adverse event was constipation. Fosaprepitant provided effective and well-tolerated control of nausea and vomiting associated with HEC in Chinese patients.


Assuntos
Antieméticos/uso terapêutico , Antineoplásicos/efeitos adversos , Morfolinas/uso terapêutico , Náusea/prevenção & controle , Vômito/prevenção & controle , Adulto , Idoso , Aprepitanto , Povo Asiático , China , Cisplatino/efeitos adversos , Dexametasona/uso terapêutico , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Granisetron/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Resultado do Tratamento , Vômito/induzido quimicamente , Adulto Jovem
8.
Trop Biomed ; 34(1): 143-149, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592992

RESUMO

Enterobius vermicularis is the most common human intestinal parasite, and its control among school children is an important public health issue. The objective of this study was to document the present situation of E. vermicularis infection in school children in Hualien. The administrative divisions in Hualien county include 13 districts (3 in a mountainous area, 10 in a rural/urban area). Between 2007 and 2012, a total of 41,191 children in 13 districts in Hualien were examined using consecutive 2-day adhesive cellophane paper perianal swabs. Our results showed Enterobius egg-positive infection rates of 5.79% (452/7,089) in 2007, 6.25% (457/7,312) in 2008, 5.37% (385/7,173) in 2009, 4.98% (330/6,804) in 2010, 4.91% (301/6,133) in 2011, and 4.68% (279/5,960) in 2012. Compared to the previously reported national average in Taiwan (range, 1.53-2.23%), the prevalence of E. vermicularis in Hualien is relatively high. The infection rates were 7.55-29.10% in mountainous areas and 0.50- 12.43% in rural/urban areas. All first and fourth grade students in elementary schools in Hualien were selected as study participants. The average infection rate of the first grade students (6.71%) was higher than that of the fourth grade students (4.23%). These results indicate that enterobiasis remains an important parasitic disease among school children in Hualien, especially those in mountainous areas.

9.
Tropical Biomedicine ; : 143-149, 2017.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-630974

RESUMO

Enterobius vermicularis is the most common human intestinal parasite, and its control among school children is an important public health issue. The objective of this study was to document the present situation of E. vermicularis infection in school children in Hualien. The administrative divisions in Hualien county include 13 districts (3 in a mountainous area, 10 in a rural/urban area). Between 2007 and 2012, a total of 41,191 children in 13 districts in Hualien were examined using consecutive 2-day adhesive cellophane paper perianal swabs. Our results showed Enterobius egg-positive infection rates of 5.79% (452/7,089) in 2007, 6.25% (457/7,312) in 2008, 5.37% (385/7,173) in 2009, 4.98% (330/6,804) in 2010, 4.91% (301/6,133) in 2011, and 4.68% (279/5,960) in 2012. Compared to the previously reported national average in Taiwan (range, 1.53–2.23%), the prevalence of E. vermicularis in Hualien is relatively high. The infection rates were 7.55–29.10% in mountainous areas and 0.50– 12.43% in rural/urban areas. All first and fourth grade students in elementary schools in Hualien were selected as study participants. The average infection rate of the first grade students (6.71%) was higher than that of the fourth grade students (4.23%). These results indicate that enterobiasis remains an important parasitic disease among school children in Hualien, especially those in mountainous areas.

10.
Cell Death Dis ; 5: e1243, 2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24853421

RESUMO

Recently, a novel class of transcripts, long non-coding RNAs (lncRNAs), is being identified at a rapid pace. These RNAs have critical roles in diverse biological processes, including tumorigenesis. Here we report that taurine-upregulated gene 1 (TUG1), a 7.1-kb lncRNA, recruiting and binding to polycomb repressive complex 2 (PRC2), is generally downregulated in non-small cell lung carcinoma (NSCLC) tissues. In a cohort of 192 NSCLC patients, the lower expression of TUG1 was associated with a higher TNM stage and tumor size, as well as poorer overall survival (P<0.001). Univariate and multivariate analyses revealed that TUG1 expression serves as an independent predictor for overall survival (P<0.001). Further experiments revealed that TUG1 expression was induced by p53, and luciferase and chromatin immunoprecipitation (ChIP) assays confirmed that TUG1 was a direct transcriptional target of p53. TUG1 knockdown significantly promoted the proliferation in vitro and in vivo. Moreover, the lncRNA-mediated regulation of the expression of HOX genes in tumorigenesis and development has been recently receiving increased attention. Interestingly, inhibition of TUG1 could upregulate homeobox B7 (HOXB7) expression; ChIP assays demonstrated that the promoter of HOXB7 locus was bound by EZH2 (enhancer of zeste homolog 2), a key component of PRC2, and was H3K27 trimethylated. This TUG1-mediated growth regulation is in part due to specific modulation of HOXB7, thus participating in AKT and MAPK pathways. Together, these results suggest that p53-regulated TUG1 is a growth regulator, which acts in part through control of HOXB7. The p53/TUG1/PRC2/HOXB7 interaction might serve as targets for NSCLC diagnosis and therapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células , Epigênese Genética , Proteínas de Homeodomínio/metabolismo , Neoplasias Pulmonares/metabolismo , RNA Longo não Codificante/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Sítios de Ligação , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Proteína Potenciadora do Homólogo 2 de Zeste , Feminino , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Proteínas de Homeodomínio/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Análise Multivariada , Estadiamento de Neoplasias , Complexo Repressor Polycomb 2/metabolismo , RNA Longo não Codificante/genética , Elementos de Resposta , Fatores de Risco , Transdução de Sinais , Fatores de Tempo , Transcrição Gênica , Transfecção , Carga Tumoral , Proteína Supressora de Tumor p53/genética
11.
Sheng Li Xue Bao ; 53(6): 456-60, 2001 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-11930225

RESUMO

Responses of afferent unit to sympathetic stimulation (SS), intravenous injection of noradrenaline (NA) and phentolamine in the caudal nerve of diabetic rats were investigated. The results showed that the discharge frequencies of C and Adelta units with spontaneous discharges were increased in diabetic hyperalgesic rats after SS, and these spontaneous discharges were eliminated by adrenergic antagonist. The C (6/21) and Adelta (19/81) units with no spontaneous discharges of diabetic hyperalgesic rat turned from silent state into active state during SS; although SS did not elicit afferent discharges of the C mechanical receptive units (C-M), it elicited afferent discharges of a part of C mechano heat units (C-MH) and C polymodal units (C-Pol); afferent discharges of some of the Adelta mechanical receptive units (Adelta-M) and Adelta mechano heat units (Adelta-MH) were also elicited by SS. The latencies of the C and Adelta units responses upon SS were not equal, but no less than 5 s. SS elicited neither afferent discharges from Abeta mechanical receptive units of diabetic hyperalgesic rat, nor receptive units of all types in the control rat. The C(3/8) and Adelta (4/12) units of diabetic hyperalgesic rat were activated by intravenous injection of NA. The present data suggest that NA released from sympathetic nerve terminals excites C and Adelta units of diabetic hypesthesic rat, which may be a peripheral factor in hyperalgesia and paresthesia of diabetic rats.


Assuntos
Cauda Equina/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Hiperalgesia/fisiopatologia , Condução Nervosa , Nociceptores/fisiopatologia , Vias Aferentes , Animais , Diabetes Mellitus Experimental/complicações , Vias Eferentes , Gânglios Simpáticos/fisiopatologia , Hiperalgesia/etiologia , Masculino , Ratos , Ratos Sprague-Dawley
12.
Appl Opt ; 40(22): 3759-61, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18360410

RESUMO

Multienergy Cu(+) ions with total dose of ~10(14) ions/cm(2) were implanted into LiNbO(3) crystals to form a nearly homogenous damage profile from the sample surface to the end of the ions' track. The extraordinary refractive-index enhancement was found in the damage region by observation of the dark mode. The extraordinary index showed an increasing trend until the ion dose reached a critical value. The largest index enhancement was ~0.0132. By use of low-dose ion implantation, we determined that the decreased spontaneous polarization caused the extraordinary index increase.

13.
Opt Lett ; 26(24): 1993-5, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18059756

RESUMO

What is believed to be the first planar optical waveguide was formed in BiB(3)O(6) (BIBO) crystal by 2.8-MeV He(+)-ion implantation with a dose of 2x10(16)ions/cm (2) and 2.8-MeV P(+)-ion implantation with a dose of 1x10(14)ions/cm (2) at room temperature. We observed 21 darks modes for the He(+)-ion-implanted BIBO waveguides and four dark modes for the P(+)-ion-implanted waveguides. The refractive-index profile of the He(+)-implanted BIBO waveguide was analyzed. The data also suggest that the BIBO waveguides formed by MeV He(+)-ion and P(+)-ion implantation differ in their developing mechanisms.

14.
J Hazard Mater ; 73(3): 209-20, 2000 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-10751692

RESUMO

It is estimated that approximately 300,000 scrap personal computers are generated each year in Taiwan [S.-L. Chang, A Study on the Scrap Computer Treatment Cost, Environment Protection Administration of Taiwan, December 1998 (in Chinese)]. The disposal of such a huge number of scrap computers presents a difficult task for the island due to the scarcity of landfills and incineration facilities available locally. Also, the hazardous materials contained (i.e., phosphor coatings of cathode ray tubes (CRTs), batteries, polychlorinated biphenyl capacitors, mercury-containing parts, liquid crystal display, high-lead content CRT funnel glass, and plastic containing flame-retardant bromine, etc.) in the scrap computers may seriously pollute the environment if they are not properly disposed of. Therefore, the EPA of Taiwan declared scrap personal computers the producer's recycling responsibility as of July 1997. Under this decree, the manufacturers, importers and sellers of personal computers have to properly recover and recycle the scrapped computers which they originally sell. On June 1, 1998, a producer responsibility recycling program for scrap computers was officially implemented in Taiwan. Under this program, consumers can bring their unwanted personal computers to the designated collection points and receive reward money. Currently, only six computer items are mandated to be recycled in this recycling program. They are notebooks, monitors, hard disks, power supplies, printed circuit boards and main frame shells. This article outlines the current scrap computer recycling system in Taiwan.


Assuntos
Conservação dos Recursos Naturais , Microcomputadores , Bromo/efeitos adversos , Discos Compactos , Periféricos de Computador , Fontes de Energia Elétrica , Eletrônica/instrumentação , Poluição Ambiental/efeitos adversos , Poluição Ambiental/prevenção & controle , Retardadores de Chama/efeitos adversos , Substâncias Perigosas/efeitos adversos , Resíduos Perigosos/efeitos adversos , Humanos , Incineração , Chumbo/efeitos adversos , Mercúrio/efeitos adversos , Bifenilos Policlorados/efeitos adversos , Eliminação de Resíduos , Taiwan
15.
Fresenius J Anal Chem ; 368(8): 797-802, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11227566

RESUMO

The design and characteristics of a novel drop-based fluorescence-detection technique for the determination of mercury(II) are described. The method, using a flow injection technique, is based on the renewable-drops of 3,3',5,5'-tetramethylbenzidine(TMB), which are formed at the bottom tip of a silica capillary tube connected to the end of the flow system. An excitation beam from a high-pressure Hg lamp directly illuminates the drops, the fluorescence emission is conducted to a photodiode (PD) to convert the photocurrent into a voltage signal (mV). Optimum analytical conditions for Hg(II) assays have been established. In NaAc/HAc buffer at pH 3.09 this assay has a wide linear range for Hg(II) from 8.0 x 10(-8) to 2.0 x 10(-5) mol/L with a detection limit of 2.0 x 10(-8) mol/L. The use of renewable drops allowing a fresh reaction surface for each sample is of particular value to solving the problems of irreversible reactions. Besides its high sensitivity, the method permits a simple, fast, and inexpensive measurement with only micro-quantities of reagent consumption. The technique described provides a simple and sensitive way to fabricate sensors of feasible prospects and commercial advantages.


Assuntos
Benzidinas , Mercúrio/análise , Fluorescência , Água Doce/análise , Indicadores e Reagentes , Sensibilidade e Especificidade , Poluentes Químicos da Água/análise
16.
Appl Opt ; 38(24): 5122-6, 1999 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-18324006

RESUMO

We formed planar waveguides in LiNbO(3) and LiTaO(3) crystals by megaelectron volt He-ion implantation. The dark modes of both waveguides are measured and their refractive-index profiles are described according to the parameterized index profile reconstruction method. The extraordinary indices of both ion-implanted waveguides exhibit quite different profiles. We compare the thermal stability of barriers in ion-implanted LiNbO(3) and LiTaO(3) waveguides by annealing at different temperatures. The results show that the barrier in a LiTaO(3) planar waveguide has higher thermal stability than that in a LiNbO(3) waveguide. The experiments also show that annealing at a temperature higher than 400 degrees C results in recrystallization of the barrier.

17.
Talanta ; 47(1): 33-42, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18967300

RESUMO

A new optical fiber sensor for monitoring tetracycline has been described, based on the fluorescence quenching of 1,4-bis(5,5'-dimethylbenzoxazole-1',3'-yl-2')benzene incorporated into a thin plasticized polymer film by tetracycline extracted from aqueous phase into film phase. The sensor is fully reversible and highly reproducible. Furthermore, the sensor exhibits a linear response to tetracycline in the range 6.98x10(-7)-8.73x10(-5) mol l(-1) with a detection limit of 1.06x10(-7) mol l(-1), and with the response time <30 s. The response is also selective to tetracycline, with some common pharmaceutical species, alkali and alkali-earth metal salts being highly discriminated, suggesting that the sensor can be used to monitor tetracycline in three pharmaceutical preparations. The recovery of tetracycline from commercial formulations is 95.3-98.3%.

18.
Talanta ; 44(7): 1319-27, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18966869

RESUMO

An optical chemical sensor has been prepared for the selective determination of o-nitrophenol in aqueous solutions based on the fluorescence quenching of curcumin in PVC membrane. The sensing mechanism of the proposed sensor for o-nitrophenol has been discussed in detail. The fluorescence changes of sensing membrane resulted from an associated complex formation between curcumin and o-nitrophenol. In pH 4.8 buffer solution, the sensor responds linearly in the measuring range from 1.0 x 10(-2) mol 1(-1) to 1.5 x 10(-4) mol 1(-1), and the experimental detection limit is evaluated to be 8.0 x 10(-5) mol 1(-1). A stable signal was obtained within less than 1.5 min. Under the optimum conditions, the sequence of selective response to the sensing membrane is o-nitrophenol > 2,4-dinitrophenol > m-nitrophenol > p-nitrophenol > 2,4,6-trinitrophenol. Phenol, aniline as well as other ions have less effect on the fluorescence of the sensor. The reproducibility for the determination of o-nitrophenol is better than 1%, and the response is reversible. The sensor can be used for the determination of o-nitrophenol in water samples.

19.
Opt Lett ; 22(3): 163-5, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18183136

RESUMO

The first planar optical waveguide to the authors' knowledge has been formed in Cu-doped potassium sodium strontium barium niobate crystal by mega-electron-volt He(+) implantation. Both TE and TM modes are observed. The profiles of the ordinary and the extraordinary refractive indices are deduced from dark-line mode spectroscopy. The results show that the mega-electron-volt He implantation results in a decrease in refractive index in barriers for both n(o) and n(e), but for n(e) there is an obvious increase in the waveguide region. From an experiment in photorefractive two-wave mixing, it is found that the erasure time for two-wave mixing is prolonged by ion implantation.

20.
Sheng Li Xue Bao ; 48(6): 536-42, 1996 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-9389151

RESUMO

While sympathetic efferents and prostaglandins (PGs) play an important role in hyperalgesia of partial injury of peripheral nerves and inflammation, whether these are also involved in diabetic hyperalgesia is unknown. With intraperitoneal injection of 6-hydroxydopamine (6-OHDA) to eliminate effects of sympathetic postganglionic neurons (SPGNs) terminals, a model of diabetic rats with infused 6-OHDA could be set up by injection of streptozotocin (STZ). Nociceptive paw-withdrawal threshold (NPWT) and tail flick latency (TFL) in 6-OHDA/diabetic rats were not changed significantly in the following four weeks. However, in diabetic group rats, pain threshold was decreased significantly and accompanied by development of hyperalgesia. NPWT was significantly decreased with noradrenaline (NA) in diabetic hyperalgesic rats and increased with phentolamine or yohimbine, but not by prazocin. In the control rats, NPWT are not changed significantly by NA or phentolamine, and in 6-OHDA/diabetic rats, neither NA nor phentolamine also affected on NPWT significantly. However, NPWT may be significantly decreased by PGE1, PGE2 and PGD2 in both the control and the diabetic hyperalgesic rats. The above results suggested that SPGNs terminals are involved in hyperalgesia of diabetic rats, NA accelerated synthesis of PGs and released by way of presynaptic effect on alpha 2-adrenergic receptors at the SPGNs terminals, PGs, in turn, directly acted on the primary afferent nociceptors, producing hyperalgesia.


Assuntos
Alprostadil/farmacologia , Diabetes Mellitus Experimental/complicações , Hiperalgesia/fisiopatologia , Nociceptores/fisiologia , Fibras Simpáticas Pós-Ganglionares/fisiopatologia , Animais , Dinoprostona/farmacologia , Vias Eferentes , Gânglios Simpáticos/fisiopatologia , Masculino , Norepinefrina/farmacologia , Oxidopamina , Limiar da Dor , Fentolamina/farmacologia , Ratos , Ratos Sprague-Dawley
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