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1.
Am J Transplant ; 17(2): 557-564, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27640901

RESUMO

Preexisting donor-specific anti-HLA antibodies (DSAs) have been associated with reduced survival of lung allografts. However, antibodies with specificities other than HLA may have a detrimental role on the lung transplant outcome. A young man with cystic fibrosis underwent lung transplantation with organs from a suitable deceased donor. At the time of transplantation, there were no anti-HLA DSAs. During surgery, the patient developed a severe and intractable pulmonary hypertension associated with right ventriular dysfunction, which required arteriovenous extracorporeal membrane oxygenation. After a brief period of clinical improvement, a rapid deterioration in hemodynamics led to the patient's death on postoperative day 5. Postmortem studies showed that lung specimens taken at the end of surgery were compatible with antibody-mediated rejection (AMR), while terminal samples evidenced diffuse capillaritis, blood extravasation, edema, and microthrombi, with foci of acute cellular rejection (A3). Immunological investigations demonstrated the presence of preexisting antibodies against the endothelin-1 receptor type A (ETA R) and the angiotensin II receptor type 1 (AT1 R), two of the most potent vasoconstrictors reported to date, whose levels slightly rose after transplantation. These data suggest that preexisting anti-ETA R and anti-AT1 R antibodies may have contributed to the onset of AMR and to the catastrophic clinical course of this patient.


Assuntos
Fibrose Cística/cirurgia , Rejeição de Enxerto/etiologia , Antígenos HLA/imunologia , Isoanticorpos/imunologia , Transplante de Pulmão/efeitos adversos , Receptor Tipo 1 de Angiotensina/imunologia , Receptor de Endotelina A/imunologia , Adulto , Sobrevivência de Enxerto , Humanos , Masculino , Complicações Pós-Operatórias , Prognóstico , Doadores de Tecidos , Transplantados
2.
Opt Express ; 23(2): 1879-87, 2015 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-25835942

RESUMO

We report a robust two-color method for super-resolution localization microscopy. Two-dye combination of Alexa647 and Alexa750 in an imaging buffer containing COT and using TCEP as switching regent provides matched and balanced switching characteristics for both dyes, allowing simultaneous capture of both on a single camera. Active sample locking stabilizes sample with 1nm accuracy during imaging. With over 4,000 photons emitted from both dyes, two-color superresolution images with high-quality were obtained in a wide range of samples including cell cultures, tissue sections and yeast cells.

3.
Phys Rev Lett ; 114(1): 010401, 2015 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-25615453

RESUMO

We propose and demonstrate an approach to measuring the biphoton temporal wave function with polarization-dependent and time-resolved two-photon interference. Through six sets of two-photon interference measurements projected onto different polarization subspaces, we can reconstruct the amplitude and phase functions of the biphoton temporal waveform. For the first time, we apply this technique to experimentally determine the temporal quantum states of the narrow-band biphotons generated from the spontaneous four-wave mixing in cold atoms.

4.
Phys Rev Lett ; 115(19): 193601, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26588379

RESUMO

We demonstrate a technique for shaping the temporal wave function of biphotons generated from spatially modulated spontaneous four-wave mixing in cold atoms. We show that the spatial profile of the pump field can be mapped onto the biphoton temporal wave function in the group delay regime. The spatial profile of the pump laser beam is shaped by using a spatial light modulator. This spatial-to-temporal mapping enables the generation of narrow-band biphotons with controllable temporal waveforms.

5.
Am J Transplant ; 14(5): 1199-206, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24612907

RESUMO

Donor-derived Strongyloides stercoralis infections in transplant recipients are a rare but recognized complication. In this case series, we report donor-derived allograft transmission of Strongyloides in three solid organ transplant recipients. Following detection of infection in heart and kidney-pancreas recipients at two different transplant centers, a third recipient from the same donor was identified and diagnosed. S. stercoralis larvae were detected in duodenal aspirates, bronchial washings, cerebrospinal fluid, urine and stool specimens. Treatment with ivermectin and albendazole was successful in two of the three patients identified. The Centers for Disease Control and Prevention was contacted and performed an epidemiologic investigation. Donor serology was strongly positive for S. stercoralis antibodies on retrospective testing while all pretransplant recipient serum was negative. There should be a high index of suspicion for parasitic infection in transplant recipients and donors from endemic regions of the world. This case series underscores the need for expanded transplant screening protocols for Strongyloides. Positive serologic or stool tests should prompt early treatment or prophylaxis in donors and recipients as well as timely notification of organ procurement organizations and transplant centers.


Assuntos
Hospedeiro Imunocomprometido , Transplante de Órgãos/efeitos adversos , Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/transmissão , Doadores de Tecidos , Adolescente , Animais , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estrongiloidíase/diagnóstico , Estrongiloidíase/parasitologia , Transplantados , Transplante Homólogo
6.
Phys Rev Lett ; 113(13): 133601, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25302886

RESUMO

We demonstrate that a single photon with an optimal temporal waveform can be efficiently loaded into a cavity. Using heralded narrow-band single photons with exponential growth wave packet shaped by an electro-optical amplitude modulator, whose time constant matches the photon lifetime in the cavity, we demonstrate a loading efficiency of (87±2)% from free space to a single-sided Fabry-Perot cavity. We further demonstrate directly loading heralded single Stokes photons into the cavity with an efficiency of (60±5)% without the electro-optical amplitude modulator and verify the time reversal between the frequency-entangled paired photons. Our result and approach may enable promising applications in realizing large-scale quantum networks based on cavity quantum electrodynamics.

7.
Small ; 9(18): 3031-6, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23520196

RESUMO

Efficient charge transfer between ZnO quantum dots (QDs) and graphene is demonstrated by decorating ZnO QDs on top of graphene, with the assistance of oxygen molecules from the air. The electrical response of the device to UV light is greatly enhanced, and a photoconductive gain of up to 10(7) can be obtained.


Assuntos
Grafite/química , Oxigênio/química , Pontos Quânticos/química , Óxido de Zinco/química
8.
Opt Express ; 21(8): 9505-13, 2013 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-23609661

RESUMO

We demonstrate the first proof of principle differential phase shift (DPS) quantum key distribution (QKD) using narrow-band heralded single photons with amplitude-phase modulations. In the 3-pulse case, we obtain a quantum bit error rate (QBER) as low as 3.06% which meets the unconditional security requirement. As we increase the pulse number up to 15, the key creation efficiency approaches 93.4%, but with a cost of increasing the QBER. Our result suggests that narrow-band single photons maybe a promising source for the DPS-QKD protocol.


Assuntos
Segurança Computacional , Modelos Teóricos , Fótons , Teoria Quântica , Processamento de Sinais Assistido por Computador , Simulação por Computador
9.
Phys Rev Lett ; 110(3): 036104, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23373939

RESUMO

Mass transport in the Pb wetting layer on the Si(111) surface is investigated by observing nonequilibrium coverage profile evolution with low energy electron microscopy and microlow energy electron diffraction. Equilibration of an initial coverage step profile occurs by the exchange of mass between oppositely directed steep coverage gradients that each move with unperturbed shape. The bifurcation of the initial profile, the shape of the profile between the two moving edges, and the time dependence of equilibration are all at odds with expectations for classical diffusion behavior. These observations signal a very unusual coverage dependence of diffusion or may even reveal an exceptional collective superdiffusive mechanism.

10.
Nano Lett ; 12(11): 5802-7, 2012 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-23051708

RESUMO

We report the piezotronic effects on the photoluminescence (PL) properties of bent ZnO nanowires (NWs). We find that the piezoelectric field largely modifies the spatial distribution of the photoexcited carriers in a bent ZnO NW. This effect, together with strain-induced changes in the energy band structure due to the piezoresistive effects, results in a net redshift of free exciton PL emission from a bent ZnO NW. At the large-size limit, this net redshift depends only on the strain parameter, but it is size-dependent if the diameter of the NW is comparable to that of the depletion layer. The experimental data obtained using the near-field scanning optical microscopy technique at low temperatures support our theoretical model.

11.
Opt Express ; 20(22): 24124-31, 2012 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-23187175

RESUMO

We report an experimental demonstration of optimal storage and retrieval of heralded single-photon wave packets using electromagnetically induced transparency (EIT) in cold atoms at a high optical depth. We obtain an optimal storage efficiency of (49 ± 3)% for single-photon waveforms with a temporal likeness of 96%. Our result brings the EIT quantum light-matter interface closer to practical quantum information applications.

12.
Phys Rev Lett ; 109(26): 263601, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23368560

RESUMO

We demonstrate coherent control of single-photon absorption and reemission in a two-level cold atomic ensemble. This is achieved by interfering the incident single-photon wave packet with the emission (or scattering) wave. For a photon with an exponential growth waveform with a time constant equal to the excited-state lifetime, we observe that the single-photon emission probability during the absorption can be suppressed due to the perfect destructive interference. After the incident photon waveform is switched off, the absorbed photon is then reemitted to the same spatial mode as that of the incident photon with an efficiency of 20%. For a photon with an exponential decay waveform with the same time constant, both the absorption and reemission occur within the waveform duration. Our experimental results suggest that the absorption and emission of a single photon in a two-level atomic ensemble may possibly be manipulated by shaping its waveform in the time domain.

13.
Opt Lett ; 36(23): 4530-2, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22139232

RESUMO

We experimentally investigate optical storage with electromagnetically induced transparency in a dense cold (85)Rb atomic ensemble. By varying the optical depth (OD) from 0 to 140, we observe that the optimal storage efficiency has a saturation value of 50% as OD>50. Our result is consistent with that obtained from hot vapor cell experiments.

14.
Phys Rev Lett ; 106(3): 033601, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21405274

RESUMO

We report the generation of nondegenerate narrow-bandwidth paired photons with time-frequency and polarization entanglements from laser cooled atoms. We observe the two-photon interference caused by Rabi splitting with a coherence time of about 30 ns and a visibility of 81.8% which verifies the time-frequency entanglement of the paired photons. The polarization entanglement is confirmed by polarization correlation measurements which exhibit a visibility of 89.5% and characterized by quantum-state tomography with a fidelity of 90.8%. Taking into account the transmission losses and duty cycle, we estimate that the system generates hyperentangled paired photons into opposing single-mode fibers at a rate of 320 pairs per second.

15.
Phys Rev Lett ; 106(24): 243602, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21770570

RESUMO

We report the direct observation of optical precursors of heralded single photons with step- and square-modulated wave packets passing through cold atoms. Using electromagnetically induced transparency and the slow-light effect, we separate the single-photon precursor, which always travels at the speed of light in vacuum, from its delayed main wave packet. In the two-level superluminal medium, our result suggests that the causality holds for a single photon.

16.
Opt Lett ; 35(11): 1923-5, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20517463

RESUMO

We report the observation of coherent two-photon free-induction decay (FID) in a three-level Lambda system excited by a low-intensity square-modulated laser pulse. Using electromagnetically induced transparency in an Rb85 cold atomic cloud, for what we believe to be the first time, we observe FID signals with coherence time exceeding the relevant atomic excited-state natural lifetime. Because of the on-resonance enhancement, the two-photon FID signal can be observed at the falling edge without using heterodyne means.

17.
Phys Rev Lett ; 104(18): 183604, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20482175

RESUMO

We experimentally demonstrate a technique for shaping the temporal quantum waveform of narrow-band biphotons generated in a cold atomic ensemble via four-wave mixing by periodically modulating the two input classical lasers. We show that it is possible to generate nonclassical paired photons with a predesigned shape of the correlation function.

18.
Phys Rev Lett ; 104(22): 223602, 2010 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-20867168

RESUMO

We report the generation of stacked optical precursors from a laser beam whose amplitude or phase is modulated by sequenced on-off step waveforms. Making use of the constructive interference between the precursors produced from different steps, as well as the main field, we generate optical transient pulses having peak powers of eight times the input power with electromagnetically induced transparency in laser-cooled atoms.


Assuntos
Lasers , Fenômenos Ópticos , Campos Eletromagnéticos
19.
Transpl Infect Dis ; 12(4): 342-6, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20030794

RESUMO

We report the case of an 18-year-old male who underwent bilateral lung transplantation for end-stage cystic fibrosis. No Epstein-Barr virus (EBV) or cytomegalovirus serology mismatch was detected on pre-transplant evaluation (donor and recipient were both positive). Two months after lung transplantation a computed tomography scan showed multiple nodules throughout both lungs. At that time a low EBV DNA blood level was detected (<300 copies/100,000 lymphomonocytes). Scheduled follow-up transbronchial biopsy (TBB) revealed a prevalent finding characterized by perivascular lymphoid infiltrates with endothelitis. Extensive tissue coagulative necrosis with peripheral areas of dense aggregates of larger lymphoid cells were detected in the trans-thoracic fine needle core biopsy (FNCB) performed on the largest nodule. The immunophenotypic profile characterized the perivascular lymphoid cells in TBB as mainly composed of T lymphocytes (CD3 positive) while the larger number of lymphocytes in FNCB as B cells (CD20 positive). In situ hybridization for EBV (EBER mRNA) was negative in TBB while it was positive in many lymphocytes of the FNCB. Real-time polymerase chain reaction (PCR) for EBV was performed on paraffin-embedded FNCB and detected a high quantity of EBV genomes (1260 copies/cell). IgH gene rearrangement using a fragment size PCR technique revealed a monoclonal B-cell population in FNCB. Morphological and molecular findings suggest a final diagnosis of acute cellular rejection and a post-transplant lymphoproliferative disorder (PTLD) EBV-related in a lung transplant recipient with a low EBV DNA blood level. A possible coexistence of PTLD and acute rejection should be considered both for diagnosis and treatment. EBV PCR in the peripheral blood is a useful screening tool in transplant recipients; however, rare cases with PTLD may not have detectable levels of EBV DNA. This aspect should be taken into consideration to avoid false negatives.


Assuntos
Infecções por Vírus Epstein-Barr/virologia , Rejeição de Enxerto/virologia , Herpesvirus Humano 4/fisiologia , Transplante de Pulmão/efeitos adversos , Transtornos Linfoproliferativos/virologia , Carga Viral/fisiologia , Doença Aguda , Adolescente , Biópsia , DNA Viral/sangue , Rejeição de Enxerto/complicações , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/isolamento & purificação , Humanos , Pulmão/patologia , Linfócitos/imunologia , Masculino , Reação em Cadeia da Polimerase/métodos
20.
J Cyst Fibros ; 19(6): e45-e47, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32674982

RESUMO

Liver involvement is not uncommon in patients with cystic fibrosis (CF). Even if serious complications as non-cirrhotic portal hypertension, cirrhosis and liver failure rarely occur, they are associated with impaired survival and reduced quality of life. Herein, we have reported the first case of a patient with CF and non-cirrhotic portal hypertension who underwent transjugular intrahepatic portosystemic shunt placement for recurrent variceal bleeding after bilateral lung transplantation, and we have reviewed the available literature pertaining to this field.


Assuntos
Fibrose Cística/complicações , Fibrose Cística/cirurgia , Hipertensão Portal/etiologia , Hipertensão Portal/cirurgia , Transplante de Pulmão , Derivação Portossistêmica Transjugular Intra-Hepática , Adulto , Humanos , Masculino
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