Neodymium-doped Yttrium Research Articles

Tracheal Hemangioma: The "Cherry" in the Trachea.

A young adult presented with a four-month long history of hemoptysis. A computed tomography (CT) scan showed a mid-trachea lesion (Figure 1). A flexible bronchoscopy was performed and revealed a cherry-like polyp (Figure 2(a)) and biopsy resulted in brisk bleeding. The polyp was coagulated at the base with a Nd-YAG (neodymium doped-yttrium aluminium garnet) laser followed by forceps resection via the rigid bronchoscope (Video). Histology of the 8 mm by 10 mm lesion was classic of a lobular capillary hemangioma (LCH) (Figure 3). The patient had been asymptomatic since and bronchoscopy performed two years later showed no tumor recurrence (Figure 2(b)). Figure 1 Computed tomography showed a homogeneously contrast enhanced polyp (white arrow) on the left lateral wall of the mid-trachea. Figure 2 (a) Distinct cherry-like polyp consistent with hemangioma arising from the left lateral wall of the mid-trachea depicted on bronchoscopy. (b) Bronchoscopy performed two years later revealed a small scar induration with normal mucosa (arrow) overlaying ... Figure 3 A nodular lesion with squamous metaplasia (marked downwards thick arrow) of the surface epithelium, underlying fibrinous exudates (marked ∗), and a florid proliferation of small capillaries (marked →) surrounded by fibrous stroma on 10x ... Lobular capillary hemangioma (LCH) is typically found on cutaneous and oronasal mucosa. Tracheobronchial LCH is a rarity [1]. Hemoptysis often occurs for a short duration ranging from weeks to months with the exception of one reported case of massive hemoptysis which required arterial embolization. The airway lesion is usually small (<10 mm), sessile, or polypoid with a distinctive glinting vascular (cherry) appearance that bleeds easily. Pathogenesis of this benign tumor is unclear and has been correlated to infections, trauma, and hormonal shifts [1]. The latter can be supported by the case of a rapidly growing trachea LCH (40 mm by 20 mm) found in a pregnant lady who presented with critical airway obstruction [2]. The characteristic findings of a homogeneously contrast enhanced lesion seen on CT scan and an airway lesion (as described above) observed during bronchoscopy should lead to a cautious biopsy to clinch the diagnosis. Bronchoscopic ablative intervention often results in a cure although past reports had a follow-up of one year or less. Ablative modalities included endoscopic resection with Nd-YAG laser, argon plasma coagulation, electrocautery, cryotherapy, and forceps. In one reported case of tumor recurrence, brachytherapy was applied.

38.5% optical-to-optical efficiency neodymium-doped yttrium vanadate/magnesium-oxide-doped periodically poled lithium niobate integrated green module with watt-level output power for laser display applications

In this paper, 1.15 W linearly polarized continuous-wave green laser is achieved from a novel neodymium-doped yttrium vanadate/magnesium-oxide-doped periodically poled lithium niobate (Nd:YVO4/MgO:PPLN) integrated packaging module (namely, mGreen) with an optical-to-optical efficiency as high as 38.5%. The presented package module is designed for mass production of green lasers at low cost to overcome the “Green” bottleneck in laser display industry.

Photodynamic therapy: where do we go from here?

Photodynamic therapy (PDT) involves the use of photosensitising agents that are selectively retained within tumour cells. The agents remain inactive until exposed to light of the proper wavelength. When activated by light, these compounds generate toxic oxygen radicals that result in tumour necrosis. In the current issue of the European Respiratory Journal , Moghissi et al. 1 have provided an exhaustive review of PDT and lung cancer. PDT appears to be a therapeutic technique, with a low toxicity profile and photosensitising agents, such as sodium porfimer, that have been approved by the Food and Drug Administration and European Agencies for the photodynamic treatment of early and late stage lung cancer. However, despite 2 decades of basic research and clinical experience, only a few centres have regular experience of PDT. Furthermore, several issues remain as yet unresolved, such as the best indications of PDT, the use of photosensitising agents other than sodium porfimer, or the comparison ofPDT and other endobronchial therapies, such as electrocautery, Neodymium-doped Yttrium …