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1.
J Vet Med Sci ; 83(1): 142-145, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33281128

RESUMO

The body surface area (BSA) of animals is generally estimated by multiplying the k value (constant) by the measured body weight (BW) raised to the power of 2/3 (Meeh's formula). Computed tomography (CT) scanners generate detailed 3-dimensional (3D) images of objects, and image analysis does not depend on operator skill. Therefore, the analysis of CT images provides accurate and reproducible BSA measurements. In this study, we measured the BSA of 25 male Hartley guinea pigs from 3 to 36 weeks of age (working BW range: 0.233 to 1.160 kg) using a CT scanner and 3D analysis software. We concluded that the k value for male Hartley guinea pigs was 8.37, based on the mean k value of the 25 animals.


Assuntos
Software , Tomografia Computadorizada por Raios X , Animais , Tamanho Corporal , Superfície Corporal/veterinária , Cobaias , Masculino , Tomografia Computadorizada por Raios X/veterinária
2.
Case Rep Oncol ; 13(3): 1337-1342, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362515

RESUMO

Hepatocellular carcinoma represents a major global health burden. Its treatment is often complicated by the anatomical location of tumors, which can lead to adverse outcomes. Radiofrequency ablation has recently gained attention as a safe method for treating hepatocellular carcinoma, but only in tumors that are not adjacent to bile ducts. Here, we report a new method for cooling the bile duct during radiofrequency ablation therapy, in which the outer jacket of an elastor needle was fixed and flash-cooled with chilled saline. This method was applied in a patient with hepatocellular carcinoma tumors near the main bile duct. The patient underwent successful radiofrequency ablation with bile duct cooling. The advantages of this method include low medical cost, simpler securing of nonexpanded bile ducts, and simultaneous removal upon termination of the radiofrequency ablation therapy. Bile duct complications associated with radiofrequency ablation typically have delayed onset. Computed tomography examination 2 months after treatment showed no bile duct injury in this case.

3.
Case Rep Oncol ; 13(1): 414-418, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32399009

RESUMO

Recently, treatment options for hepatocellular carcinoma (HCC) have expanded due to the development of the tyrosine kinase inhibitor ramucirumab and immune checkpoint inhibitors. Transcatheter arterial chemoembolization is the standard therapy for intermediate-stage HCC; however, in cases with anatomical problems, normal approaches are not possible. In such rare cases, direct hepatic puncture may be considered as an effective therapy and an indispensable treatment. We report our novel method of direct hepatic artery puncture in this case report. In 2011 and 2017, we reported 2 cases in the journal of the Japan Society of Hepatology in Japanese. This therapy is difficult and is associated with a high risk of complications; however, we succeeded in both cases in a similar way. We believe this method may provide an alternative treatment when standard treatment is not possible or when urgent therapy is required. In case 1, direct hepatic artery puncture was performed under ultrasonographic guidance, and we were able to control the disease with percutaneous lipiodol chemotherapy. Case 2 was an emergency case of ruptured HCC. Direct hepatic puncture successfully stopped tumor bleeding; furthermore, tumor necrosis also occurred, as seen on the enhanced computed tomography image. Our new method requires advanced puncture techniques and is not the treatment of choice if there are other safe alternatives available. However, it can be considered as an option if there are no other viable, effective treatments.

4.
Exp Anim ; 68(4): 429-434, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31092747

RESUMO

The body surface area (BSA) of animals has generally been estimated by multiplying the k value by the measured body weight (BW) raised to the power of 2/3 (Meeh's formula). In mathematical terms, the assumption that the density and body shape of animals are essentially constant means that the BSA is proportional to BW2/3. In this study, we measured the BSA and volume of 50 male Japanese White rabbits (JW) at 10 to 54 weeks of age using a computed tomography scanner, then calculated the k value, density, and sphericity. The variations in these parameters were then analyzed in relation to growth. The obtained results indicated that the k value was negatively correlated to BW, and that this negative correlation was mainly due to the variation in density. Based on the regression analysis, we propose the following linear regression equation for calculating the k value in male JW at 10-54 weeks of age: the k value = 14.602 - 0.959 × BW [kg]. The calculated values ranged from 10.9 to 12.7 (working BW range: 1.98 to 3.81 kg). The k value of male New Zealand White rabbits (NZW) determined in our previous study and that of male JW in the present study were compared. It was revealed that the k value of male JW was larger than that of male NZW. We concluded that different breeds of rabbits express different k values.


Assuntos
Tamanho Corporal , Superfície Corporal , Coelhos/fisiologia , Tomógrafos Computadorizados/estatística & dados numéricos , Tomografia Computadorizada por Raios X , Animais , Masculino , Especificidade da Espécie
5.
Exp Anim ; 67(4): 527-534, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29998917

RESUMO

The body surface area (BSA) of an organism is one of the important parameters for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying the k value by 2/3 of the power of the body weight (BW) (Meeh's formula). In mathematics, if it is assumed that the density and body shape of the animals are essentially constant, the BSA is proportional to BW2/3. In this study, we measured the BSA and volume (V) of 72 laboratory rabbits (48 males and 24 females of New Zealand White rabbits [NZW]), using a computed tomography scanner. After BSA and V determination, the k value, density, and sphericity were calculated. We analyzed variations in the k value, density, and body shape of laboratory rabbits. The mean k value of the 72 NZW was 11.0. We advocate using Meeh's formula, as follows, for estimating BSA of laboratory rabbits (NZW): 100 × BSA [m2] = 11.0 × BW [kg]2/3.


Assuntos
Animais de Laboratório/anatomia & histologia , Superfície Corporal/veterinária , Coelhos/anatomia & histologia , Tomografia Computadorizada por Raios X , Animais , Feminino , Masculino
6.
Exp Anim ; 66(3): 229-233, 2017 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-28367864

RESUMO

The use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing in recent years. It is anticipated that the use of juvenile miniature pigs in laboratory practice will also increase. Therefore, it is important to investigate various parameters of juvenile miniature pigs. The body surface area (BSA) of an organism is one of the important parameters for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying the k value by 2/3 of the power of the body weight (BW) (Meeh's formula). To our knowledge, the BSA of juvenile miniature pigs has not as yet been reported. In this study, we measured the BSA of 13 miniature pigs less than 1 month old, using a computed tomography scanner and 3-dimensional analysis software. The measurement results showed the BSAs of these 13 juvenile miniature pigs to be in the range of 386 to 1,672 cm2(working BW range: 278 to 3,200 g). After BSA determination, the k values were calculated from the BSA and the BW. The mean calculated k value was 8.58. We advocate using Meeh's formula, as follows, for estimating the BSA of juvenile miniature pigs less than 1 month old (before weaning): BSA (cm2)=8.58 × BW (g)2/3.


Assuntos
Animais de Laboratório/anatomia & histologia , Superfície Corporal/veterinária , Porco Miniatura/anatomia & histologia , Porco Miniatura/fisiologia , Tomografia Computadorizada por Raios X , Animais , Peso Corporal , Imageamento Tridimensional , Software , Suínos
7.
J Toxicol Sci ; 41(5): 637-44, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27665773

RESUMO

The body surface area (BSA) of an organism is an important parameter for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying a constant by the power of the body weight (BW). Recently, the use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing. However, verification of their BSA is not as yet sufficient. In this study, we measured the BSAs of 40 laboratory miniature pigs (11 males and 9 females of Göttingen minipig and 14 males and 6 females of Nippon Institute for Biological Science [NIBS] miniature pig) by analyzing computed tomography (CT) images, since measurements using a CT scanner were expected to more precisely determine BSA than classical measuring techniques. The measurement results showed the BSAs of the 20 Göttingen minipigs to range from 0.4358 to 0.8356 m(2) (the working BW range: 12.7-37.0 kg) and 20 NIBS miniature pigs to range from 0.2906 to 0.8675 m(2) (the working BW range: 7.9-41.5 kg). Since accuracy and reproducibility were confirmed by measuring the surface area of an acrylic cuboid, we concluded the measurement method employed in this study to be very reliable. We propose the following estimating formula for BSA of laboratory miniature pigs: 100 × BSA [m(2)] = 7.98 × BW [kg](2/3).


Assuntos
Superfície Corporal , Tomógrafos Computadorizados , Tomografia Computadorizada por Raios X/instrumentação , Animais , Peso Corporal , Feminino , Imageamento Tridimensional , Masculino , Modelos Biológicos , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Fatores Sexuais , Especificidade da Espécie , Suínos , Porco Miniatura
8.
Case Rep Gastroenterol ; 9(1): 88-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25969675

RESUMO

A 63-year-old woman was admitted because of epigastric pain and obstructive jaundice. Endoscopic retrograde cholangiopancreatography and intraductal ultrasonography revealed a 25-mm papillary nodule in the middle to inferior portion of the common bile duct (CBD). Pancreaticobiliary maljunction (PBM) was also identified. Contrast-enhanced computed tomography also showed an enhanced nodule in the CBD, and we suspected intraductal papillary neoplasm of the bile duct. We performed pylorus-preserving pancreatoduodenectomy. Postoperative pathological examination revealed an inflammatory polyp in the middle CBD. Inflammatory polyp in the bile duct is rare and there are no previous reports accompanied by PBM. PBM is a major risk factor for biliary tract cancer. Preoperative diagnosis of a benign disorder was difficult in this case.

9.
Surg Endosc ; 29(6): 1400-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25159649

RESUMO

BACKGROUND: Small bowel obstruction secondary to intra-abdominal adhesions is a frequent postoperative complication. Less invasive surgery carries a lower risk of postoperative adhesions, but adhesions may still occur after laparoscopic colorectal surgery. We present here some of our methods of adhesion prophylaxis for laparoscopic colorectal surgery. METHODS: The 167 patients who underwent laparoscopic colorectal surgery at our center from 2007 to 2012 were retrospectively reviewed. To prevent postoperative intra-abdominal adhesions, anti-adhesion barriers were placed using the half-overlap method. The rate of postoperative small bowel obstruction was compared among three groups: patients who received no adhesion prophylaxis (Group NP), patients who received single-layered adhesion prophylaxis adjacent to the incision (Group SP), and patients who received three layers of adhesion prophylaxis at different depths (Group MLP). RESULTS: The rate of postoperative ileus was significantly different among the three groups, at 9.7 % (6/62) in Group NP, 5.0 % (1/19) in Group SP, and 0 % (0/86) in Group MLP). CONCLUSIONS: This retrospective analysis found that placement of multi-layered anti-adhesion barriers using the half-overlap method provided the most effective prophylaxis. Prospective clinical trials are needed to further evaluate these methods of anti-adhesion prophylaxis.


Assuntos
Cirurgia Colorretal/métodos , Ácido Hialurônico/uso terapêutico , Obstrução Intestinal/cirurgia , Laparoscopia/efeitos adversos , Aderências Teciduais/prevenção & controle , Adulto , Cirurgia Colorretal/efeitos adversos , Feminino , Humanos , Obstrução Intestinal/etiologia , Intestino Delgado/cirurgia , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Aderências Teciduais/etiologia
10.
World J Gastroenterol ; 18(41): 5979-81, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23139616

RESUMO

Liposarcoma is one of the most common soft tissue sarcomas found in adults, and it usually occurs in the retroperitoneum and the extremities. Here, we describe a case of dedifferentiated liposarcoma originating from a well-differentiated liposarcoma of the mesorectum that presented as a protruding mass in the rectal lumen. Hartmann's operation with total mesorectal excision was performed and the tumor was removed radically. No management guidelines are currently available for liposarcoma of the rectum. We propose that complete surgical resection be required for the treatment of rectal liposarcoma and that a long-term detailed follow up is necessary.


Assuntos
Desdiferenciação Celular , Neoplasias Retais/patologia , Sarcoma/patologia , Idoso , Biomarcadores Tumorais/análise , Biópsia , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Retais/química , Neoplasias Retais/cirurgia , Sarcoma/química , Sarcoma/cirurgia , Fatores de Tempo , Resultado do Tratamento
11.
Gan To Kagaku Ryoho ; 39(5): 847-9, 2012 May.
Artigo em Japonês | MEDLINE | ID: mdl-22584347

RESUMO

We report two cases of advanced pancreatic cancer treated with CPT-11 and CDDP as third-line chemotherapy. CPT-11 was administered as an intravenous injection at a dose of 60 mg/m², and CDDP was administered at a dose of 30 mg/m2 biweekly. The patients showed no adverse events greater than grade 2 toxicity, and these adverse events were tolerated. The patients showed partial response and stable disease. These results suggested that this treatment schedule was safe and effective for progressive pancreatic cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Camptotecina/análogos & derivados , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Humanos , Irinotecano , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Pancreáticas/patologia , Tomografia Computadorizada por Raios X
12.
Gan To Kagaku Ryoho ; 38(6): 1025-7, 2011 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-21677501

RESUMO

The patient was a 70-year-old male who had multiple lung metastases of rectal cancer. He was administered UFT(300mg/ day)and LV(75mg/day)after Hartmann operation for rectal cancer. He complained of fever and difficulty breathing after 2 courses of these medicines, and was admitted for UFT-and LV-induced interstitial pneumonitis. Treatment with methylpredni- solone(30mg/day)improved his symptoms and revealed radical findings. He was ready for discharge on the 10th day after treatment. Interstitial pneumonitis-induced UFT and LV is rare, but can lead to severe complications, which should be diagnosed and treated by corticosteroid as soon as possible.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Leucovorina/efeitos adversos , Doenças Pulmonares Intersticiais/induzido quimicamente , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Retais/tratamento farmacológico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Humanos , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Masculino , Neoplasias Retais/patologia , Tegafur/administração & dosagem , Tegafur/efeitos adversos , Tegafur/uso terapêutico , Tomografia Computadorizada por Raios X , Uracila/administração & dosagem , Uracila/efeitos adversos , Uracila/uso terapêutico
13.
J Toxicol Pathol ; 22(4): 255-61, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22272000

RESUMO

To clarify the modifying effect of N-Acetyl-L-Cysteine (NAC), which has antioxidative ability, on hepatocarcinogenesis promoted by fenofibrate (FF), a peroxisome proliferator-activated receptor (PPAR) alpha agonist , male F344/N rats were administered a single intraperitoneal injection of N-diethylnitrosamine (DEN) as an initiator followed by administration of a diet containing 3,000 ppm of FF for 16 weeks. Two-thirds partial hepatectomy was performed 1 week after the FF treatment. Additionally, NAC treatments for 14 weeks from 2 weeks after the FF treatment were performed. Although the expression level of tumor protein p53 (Tp53) mRNA decreased in the DEN+FF+NAC group as compared with that in the DEN+FF group, no significant differences between the DEN+FF and DEN+FF+NAC groups were observed in the number of hepatocellular altered foci and activities of hepatocellular proliferation. In addition, the results of an antioxidant enzyme assay and measurement of the amounts of total glutathione in the liver revealed no significant difference between the DEN+FF and DEN+FF+NAC groups; although no significant differences were observed in many genes between the DEN+FF and DEN+FF+NAC groups, only glutathione peroxidase 2 (Gpx2) mRNA increased in the DEN+FF+NAC group as compared with the DEN+FF group. The results under the present experimental conditions indicate no obvious modifying effect of NAC on liver tumor promotion by FF in rats.

14.
Phys Rev Lett ; 103(25): 257401, 2009 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-20366280

RESUMO

We report the observation of a remarkably strong coupling between light and a multinode-type exciton. The observed radiative decay time reaches the order of 100 fs, which is much faster than the dephasing process of nonradiative scattering. In this high-speed superradiance, the light wave and the excitonic wave in a high-quality thin film form a harmonized wave-wave coupling over a range of multiple wavelengths. This mechanism contradicts the conventional physical description of light-matter interaction based on the long-wavelength approximation.

15.
Toxicology ; 231(2-3): 234-42, 2007 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-17254688

RESUMO

In order to examine whether the in vivo initiation activity of a new quinolone antimicrobial agent -- norfloxacin (NFLX) -- results in the induction of hepatocellular tumors, F344 male rats were subjected to two-thirds partial hepatectomy and oral administration of 1500 or 750mg/kg BW of NFLX or the vehicle once daily for 3 weeks. From 2 weeks after the completion of NFLX treatment, the rats were given 500ppm phenobarbital (PB) in their drinking water for 51 weeks. After the promotion treatment with PB for 17, 34, or 51 weeks, the rats were euthanized under ether anesthesia, and the NFLX-induced hepatic tumors were examined macroscopically by thoroughly sectioning the liver at 5-mm intervals. The liver slices, one each from all liver lobes, were fixed in 10% neutral buffered formalin for immunohistochemical examination of glutathione S-transferase placental form (GST-P) positive foci. NFLX increased neither the incidence of macroscopic hepatic tumors nor the mean number or area of GST-P positive foci. These results suggest that under the present study conditions, the initiation activity of NFLX does not result in the induction of hepatocellular tumors in rats; thus, the initiation activity of NFLX is extremely weak.


Assuntos
Anti-Infecciosos/toxicidade , Carcinógenos/toxicidade , Carcinoma Hepatocelular/etiologia , Neoplasias Hepáticas/etiologia , Norfloxacino/toxicidade , Administração Oral , Animais , Testes de Carcinogenicidade , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/patologia , Relação Dose-Resposta a Droga , Glutationa Transferase/metabolismo , Hepatectomia , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/patologia , Masculino , Fenobarbital/farmacologia , Ratos , Ratos Endogâmicos F344
16.
J Phys Condens Matter ; 19(18): 186210, 2007 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-21690991

RESUMO

Fundamental magneto-optical properties of single crystals of the semimagnetic semiconductor Cd(0.8)Mn(0.2)Te are carefully measured with the use of band-to-band excitation. Two new phenomena are presented: the peculiar magnetic field dependence of the magnetic polaron luminescence and the existence of two components for the polaron luminescence. Theoretical consideration with regard to the Zeeman effect ascribes the two components of luminescence to the exciton magnetic polaron spectrum and the neutral acceptor-bound exciton magnetic polaron spectrum. The calculated result for the luminescence peak positions is also consistent with the experimental result of the circularly polarized luminescence under the presence of an applied magnetic field. In other words, the σ(+) luminescence is due to the exciton magnetic polaron, whereas the σ(-) luminescence is due to the neutral acceptor-bound exciton magnetic polaron.

17.
Toxicology ; 222(3): 240-6, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16580113

RESUMO

This study aimed to examine the in vivo initiation activity of the quinolone antimicrobials--nalidixic acid (NA), pipemidic acid (PPA), ciprofloxacin (CPFX), and norfloxacin (NFLX)--by using an in vivo short-term liver initiation assay. Rats were subjected to a two-thirds partial hepatectomy on day 0 and 12 h after completion of this procedure were treated once orally with each quinolone or vehicle. Subsequently, they were fed a basal diet for 14 days and a diet containing 0.015% of 2-acetylaminofluorene for the following 10 days. On day 19, a single oral dose of carbon tetrachloride at 0.8 mL/kg body weight was administered. On day 34, they were sacrificed under ether anesthesia, and liver slices were fixed in 10% neutral buffered formalin for immunohistochemical examination of glutathione S-transferase placental form (GST-P) positive foci. Administration of NFLX resulted in a significant increase in the mean number and area of GST-P positive foci; however, administration of the three other quinolones did not produce any increase. These results suggest that only NFLX has an initiation activity in rats under the conditions used in the present study.


Assuntos
Anti-Infecciosos/toxicidade , Fígado/efeitos dos fármacos , Norfloxacino/toxicidade , 2-Acetilaminofluoreno/toxicidade , Animais , Tetracloreto de Carbono/toxicidade , Carcinógenos/toxicidade , Ciprofloxacina/toxicidade , Glutationa Transferase/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Ácido Nalidíxico/toxicidade , Ácido Pipemídico/toxicidade , Ratos , Ratos Endogâmicos F344
18.
Mutat Res ; 603(2): 135-44, 2006 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-16384725

RESUMO

The purpose of this study was to examine the genotoxicity of quinolone antimicrobials. We investigated the genotoxic potential of eight quinolones, namely nalidixic acid (NA), pipemidic acid (PPA), oxolinic acid (OA), piromidic acid (PA), enoxacin (ENX), ofloxacin (OFLX), norfloxacin (NFLX) and ciprofloxacin (CPFX), by the in vitro alkaline single-cell gel electrophoresis (comet) assay at pH>13. WTK-1 cells (mutant p53) were treated with each of the eight quinolones at 62.5-1000 microg/mL for 2, 4 and 20 h. NFLX and CPFX significantly induced DNA damage concentration-dependently after 4 and 20 h treatment, but this damage was recoverable. On the other hand, DNA was not damaged in the cells treated with six other quinolones. In the cells treated with NFLX and CPFX for 20 h, DNA migration was compared by the comet assay at pH 10, 12.1 and >13. The comet assay both at pH 12.1 and >13 showed increased DNA migration, but there was no positive response in the comet assay at pH 10. In the in vitro micronucleus (MN) test, WTK-1 cells were treated with each of four quinolones (NA, PPA, NFLX and CPFX) at 15.63-125 microg/mL for 20 h. NFLX significantly increased MNs in the cells, but no changes were noted in the cells treated with three other quinolones. These results suggest that NFLX and CPFX induced DNA single strand breaks (SSBs), and that NFLX-induced SSBs resulted in chromosome aberrations.


Assuntos
Anti-Infecciosos/toxicidade , Aberrações Cromossômicas , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Testes para Micronúcleos , Quinolonas/toxicidade , Humanos , Técnicas In Vitro , Linfoma/tratamento farmacológico , Mutação/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
19.
J Phys Condens Matter ; 18(6): 1967-75, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21697569

RESUMO

The dependences of cathodoluminescence (CL) from ZnO:Zn phosphor powder upon local space, accelerating voltage and beam current have been investigated at room temperature. Ultraviolet (UV) luminescence, which is hard to be observed in photoluminescence (PL) at room temperature, has been clearly observed in CL as well as green luminescence. The intensity ratio of the UV luminescence to the green one varies from point to point. From the comparison with PL, the UV luminescence is attributed to the recombination of ZnO free excitons. The UV luminescence is little observed at low accelerating voltage where, similar to the excitation light for PL measurement, the electron beam penetrates into only the surface depletion layer where free excitons are unstable due to the surface electric field. However, the UV luminescence from the depletion layer becomes observable at large beam current because of the suppression of the electric field in the depletion layer caused by injected electrons.

20.
Nature ; 431(7005): 167-70, 2004 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-15356626

RESUMO

Entanglement is one of the key features of quantum information and communications technology. The method that has been used most frequently to generate highly entangled pairs of photons is parametric down-conversion. Short-wavelength entangled photons are desirable for generating further entanglement between three or four photons, but it is difficult to use parametric down-conversion to generate suitably energetic entangled photon pairs. One method that is expected to be applicable for the generation of such photons is resonant hyper-parametric scattering (RHPS): a pair of entangled photons is generated in a semiconductor via an electronically resonant third-order nonlinear optical process. Semiconductor-based sources of entangled photons would also be advantageous for practical quantum technologies, but attempts to generate entangled photons in semiconductors have not yet been successful. Here we report experimental evidence for the generation of ultraviolet entangled photon pairs by means of biexciton resonant RHPS in a single crystal of the semiconductor CuCl. We anticipate that our results will open the way to the generation of entangled photons by current injection, analogous to current-driven single photon sources.

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