Modulation and real-time monitoring of the carrier-envelope phase of terahertz pulses based on shaping of near-infrared femtosecond pulses.

We propose a novel, to our knowledge, method for modulating and real-time monitoring of the carrier-envelope phase (CEP) of terahertz (THz) pulses. CEP is an essential parameter in the interaction of THz waves with matter due to the difference in temporal symmetry when the carrier is extended for several cycles. CEP can be continuously modulated at full range with high speed by oscillating the optical path length of the Michelson interferometer under 1 µm, as confirmed by electro-optic (EO) sampling. The proposed method can be combined with a data acquisition method that links the experimental parameters and measurements of individual high-repetition THz pulses to realize robust CEP modulation measurements. As the proposed CEP modulation and monitoring system does not require EO sampling but only extracts CEP dependence, the trend toward ultrafast physical property control and observation using THz pulses will spread to other fields.

Digital phase conjugate mirror by parallel arrangement of two phase-only spatial light modulators.

In a conventional digital phase conjugation system, only the phase of an input light is time-reversed. This deteriorates phase conjugation fidelity and restricts application fields to specific cases only when the input light has uniformly-distributed scattered wavefront. To overcome these difficulties, we present a digital phase conjugate mirror based on parallel alignment of two phase-only spatial light modulators (SLMs), in which both amplitude and phase of the input light can be time-reversed. Experimental result showed that, in the phase conjugation through a holographic diffuser with diffusion angle of 0.5 degree, background noises decrease to 65% by our digital phase conjugation mirror.

Selective multimode excitation using volume holographic mode multiplexer.

We propose a mode multiplexer based on volume holograms to realize a simple and efficient mode-division-multiplexed transmission system that supports a large number of modes. Selective multiexcitation of three spatial modes into a conventional multimode fiber is experimentally demonstrated. This device could potentially multiplex 10 or more modes. Future perspectives of the mode multiplexer for application in mode-division multiplexing are also discussed.

Increased plasma levels of big-endothelin-2 and big-endothelin-3 in patients with end-stage renal disease.

AIMS: Big endothelins (pro-endothelin; inactive-precursor) are converted to biologically active endothelins (ETs). Mammals and humans produce three ET family members: ET-1, ET-2 and ET-3, from three different genes. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3, which is produced by neuronal cells and organs such as the thyroid, salivary gland and the kidney. In patients with end-stage renal disease, abnormal vascular endothelial cell function and elevated plasma ET-1 and big ET-1 levels have been reported. It is unknown whether big ET-2 and big ET-3 plasma levels are altered in these patients. The purpose of the present study was to determine whether endogenous ET-1, ET-2, and ET-3 systems including big ETs are altered in patients with end-stage renal disease. MAIN METHODS: We measured plasma levels of ET-1, ET-3 and big ET-1, big ET-2, and big ET-3 in patients on chronic hemodialysis (n=23) and age-matched healthy subjects (n=17). KEY FINDINGS: In patients on hemodialysis, plasma levels (measured just before hemodialysis) of both ET-1 and ET-3 and big ET-1, big ET-2, and big ET-3 were markedly elevated, and the increase was higher for big ETs (Big ET-1, 4-fold; big ET-2, 6-fold; big ET-3: 5-fold) than for ETs (ET-1, 1.7-fold; ET-3, 2-fold). SIGNIFICANCE: In hemodialysis patients, plasma levels of the inactive precursors big ET-1, big ET-2, and big ET-3 levels are markedly increased, yet there is only a moderate increase in plasma levels of the active products, ET-1 and ET-3. This suggests that the activity of endothelin converting enzyme contributing to circulating levels of ET-1 and ET-3 may be decreased in patients on chronic hemodialysis.

Continuous intravenous administration of a low dose of epoprostenol greatly decreased serum concentrations of endothelin-1 in primary pulmonary hypertension--a case report.

Endothelin-1 (ET-1) is known to be a principal factor in the pathogenesis of primary pulmonary hypertension (PPH). Recently intravenous administration of epoprosterol improved the survival rate in PPH. However, the effect of epoprosterol on ET-1 remains to be investigated. Therefore, we studied a patient with PPH who was treated with a low dose of epoprosterol and examined the serum concentration of ET-1 during the treatment. Epoprosterol greatly decreased the serum concentration of ET-1 in parallel with improvement of the clinical course, suggesting that ET-1 level may be a marker for treatment of PPH.

Cerebral metastasis from angiosarcoma of the aortic wall: case report.

BACKGROUND: Primary or metastatic cerebral angiosarcoma is extremely rare, and only limited cases have been reported. The authors here describe a case of angiosarcoma, which was initially identified and diagnosed by the cerebral metastatic lesion; later examinations suggested that the primary site was the abdominal aorta. CASE DESCRIPTION: A 53-year-old man, who had suffered an abdominal aortic aneurysm 2 months earlier, experienced a sudden onset of left-sided hemifacial convulsion and dysarthric speech. Computed tomography (CT) showed a hemorrhagic mass lesion with perifocal edema in the right frontal lobe. Magnetic resonance imaging (MRI) showed a regionally marked hypointensity in the mass lesion on both T1- and T2-weighted images, which might suggest hemosiderin deposition. The tumor was removed in its entirety. Pathologic examination revealed an old hematoma with a hemosiderin deposit containing markedly atypical tumor cells, and angiosarcoma was diagnosed. Resection of the abdominal aortic aneurysm and iliac bone biopsy were performed and angiosarcoma was recognized in each surgical specimen. Based on clinical and pathologic findings, the primary site was considered to be the abdominal aorta. CONCLUSIONS: Clinicians should be aware of this rare histologic type of tumor. Unique MRI findings such as those obtained in our case might be useful for differentiating this condition from other intracranial neoplasms.

Discharge diagnoses in infants with apparent life-threatening event.

BACKGROUND: There are various identifiable diseases or conditions that can be associated with an apparent life-threatening event (ALTE) in infancy. The present study was carried out to investigate the etiology of ALTE based on the discharge diagnoses. METHODS: A protocol for the complete work-up used to examine the cause of ALTE was designed, and was carried out for 69 infants with ALTE. RESULTS: Gastroesophageal reflux disease (GERD) was demonstrated in 38 cases, and chronic gastric volvulus (CGV) was diagnosed in 21 (associated with GERD in 13 infants). Four cases of pertussis and two cases each of sepsis, laryngomalacia, respiratory immaturity, and premature ventricular contractions were found. Others cases presented with pneumonia, meningitis, intussuception, food allergy, epilepsy, and adenoid vegetations. In 12 of the 69 infants with ALTE, no abnormalities were found in any of the studies performed, including two patients with breath-holding spells. In 17 cases, two or more possibly contributing findings were diagnosed. CONCLUSION: It is important to recognize that gastroesophageal impairments such as GERD or CGV could be responsible for many incidences of ALTE in infancy. The authors recommend a trial be established to investigate the causes of ALTE, including gastroesophageal evaluations in all infants with ALTE.