Quantum illumination using polarization-path entangled single photons for low reflectivity object detection in a noisy background.

Detecting object with low reflectivity embedded within a noisy background is a challenging task. Quantum correlations between pairs of quantum states of light, though are highly sensitive to background noise and losses, offer advantages over traditional illumination methods. Instead of using correlated photon pairs which are sensitive, we experimentally demonstrate the advantage of using heralded single-photons entangled in polarization and path degree of freedom for quantum illumination. In the study, the object of different reflectivity is placed along the path of the signal in a variable thermal background before taking the joint measurements and calculating the quantum correlations. We show the significant advantage of using non-interferometric measurements along the multiple paths for single photon to isolate the signal from the background noise and outperform in detecting and ranging the low reflectivity objects even when the signal-to-noise ratio is as low as 0.03. Decrease in visibility of polarization along the signal path also results in similar observations. This will have direct relevance to the development of single-photon based quantum LiDAR and quantum imaging.

Widely tunable room-temperature continuous-wave optical parametric oscillator based on periodically-poled KTiOPO4.

We report the first realization of widely tunable continuous-wave (cw) optical parametric oscillator (OPO) based on periodically-poled KTiOPO4 (PPKTP) at room temperature. By exploiting fan-out grating design in a 30-mm PPKTP crystal, and configured in an output-coupled singly-resonant oscillator (OC-SRO) configuration pumped at 532 nm in the green, the OPO provides finely tunable radiation across 741-922 nm in the signal and 1258-1884 nm in the idler, at a fixed temperature of 25 °C. The use of output coupling for the signal wave enables enhancement of OPO extraction efficiency to 30%, providing a maximum total output power of 1.65 W (450 mW of signal at 901 nm and 1.2 W of idler at 1299 nm) for 5.5 W of pump power. The output idler exhibits passive power stability better than 3.2% rms over >2 mins, and the extracted signal exhibits frequency stability of 194 MHz over more than 35 seconds, in excellent beam quality. The OPO performance in pure SRO configuration has also been investigated.

SHG (532 nm)-induced spontaneous parametric downconversion noise in 1064-nm-pumped IR upconversion detectors.

As a novel technique for infrared detection, frequency upconversion has been successfully deployed in many applications. However, investigations into the noise properties of upconversion detectors (UCDs) have also received considerable attention. In this Letter, to the best of our knowledge, we present a new noise source-second-harmonic generation (SHG)-induced spontaneous parametric downconversion-experimentally and theoretically shown to exist in short-wavelength-pumped UCDs. We investigate the noise properties of two UCDs based on single-pass 1064-nm-pumped periodically poled LiNbO3 bulk crystals. One UCD is designed to detect signals in the telecom band and the other in the mid-infrared regime. Our experimental demonstration and theoretical analysis reveal the basic properties of this newly discovered UCD noise source, including its dependence on crystal temperature and pump power. Furthermore, the principle behind the generation of this noise source can also be applied to other UCDs, which utilize nonlinear crystals either in waveguide form or with different bulk materials. This study may also aid in developing methods to suppress the newly identified noise in future UCD designs.

Multimilliwatt, tunable, continuous-wave, mid-infrared generation across 4.6-4.7 µm based on orientation-patterned gallium phosphide.

We report the generation of tunable continuous-wave (cw) mid-infrared (mid-IR) radiation across 4608-4694 nm using the new nonlinear material, orientation-patterned gallium phosphide (OP-GaP). By exploiting difference-frequency mixing between a cw Tm-fiber laser and a home-built cw optical parametric oscillator in a 40-mm-long crystal, we have generated up to 43 mW of cw output power, with >30 mW across >95% of the mid-IR tuning range. The output at 4608 nm exhibits high beam quality with a passive power stability of 2.5% rms over 1.5 min. The temperature acceptance bandwidth of the OP-GaP crystal has been measured and compared with theory. The performance of the mid-IR source at high pump powers and polarization-dependent transmission in OP-GaP has been investigated.

Future prospects of systemic host modulatory agents in periodontal therapy.

Periodontitis is an inflammatory disease caused by microbial infection that leads to destruction of supporting tissues of the teeth. The periodontal tissue destruction is a result of both microbial activity as well as host response. The best chance for clinical improvement may come from implementing complementary treatment strategies that target different aspects of the periodontal balance. Host response modulation, in combination with conventional treatment, offers to restore the balance between health and disease progression in the direction of a healing response. Various host modulatory therapies (HMT) have been developed or proposed to block pathways responsible for periodontal tissue break down. The newer drugs like bortezomib, infliximb, etanercept, vasoactive intestinal peptide, nitric oxide synthase inhibitors and denosumab are developed as a result of better understanding of pathogenesis of inflammatory tissue destruction and may represent the future of periodontal therapy. This review article focuses on the potential systemic host modulatory agents that target cell signalling pathways, cytokines and enzymes.

Coccidioidomycosis in India: Report of a third imported case.

We describe the third fatal case of imported coccidioidomycosis in India in a 31-year-old mechanical engineer originally from Andhra Pradesh, India, who lived in Gwinner, North Dakota. He had traveled to Arizona in summer of 2006, where he drove tractors in a dusty environment at a tractor production facility near Phoenix, Arizona. He was human immunodeficiency virus (HIV) positive. Initially, he was treated in Fargo, North Dakota, in 2006, with liposomal amphotericin B followed by oral fluconazole. Antiretroviral treatment for HIV infection was started. He moved back to India and was admitted to the intensive care unit of St. John's Medical College and Hospital, Bangalore, India. His blood cultures yielded Coccidioides sp. The identity of the isolate was confirmed using the Gen Probe Accuprobe test at the Centers for Disease Control and Prevention, Atlanta, Georgia. In spite of initiation of treatment with antifungal agents (amphotericin B and fluconazole), his condition deteriorated and he expired three days following his admission to the hospital.

Removal of migrated metallic prostatic stent by holmium laser.

A 90-year-old male with prostatic hyperplasia with a history of ischemic heart disease and right-sided hemiplegia had undergone a Urolume stent placement because of acute urinary retention 9 months earliar. The stent had migrated into the bladder causing dysuria and a poor stream of urine. We fragmented the prostatic stent by Holmium (HO: YAG) laser followed by a laser prostatectomy. After the procedure, the patient voided satisfactorily.

Is stenting required before retrograde intrarenal surgery with access sheath.

BACKGROUND: Flexible ureterorenoscopies continue to assume an increasing role in the armamentarium of the endourologist. In many centers around the world, prior stenting is carried out before retrograde intrarenal surgery (RIRS) to passively dilate the ureter, which facilitates passage of a flexible ureteroscope with or without an access sheath. In our series, the first stage of passive dilatation with prior stenting was totally avoided without compromising the success of the procedure. MATERIALS AND METHODS: From January 2004 to December 2007, 54 patients with 55 renal units underwent RIRS. The patients were between 28 and 65 years old. All patients had renal stones ranging in size from 8 mm to 22 mm. The mean serum creatinine level was 1.1 mg%. The lower ureter was dilated under 'C - arm' fluoroscopy guidance up to 14 FR. An access sheath of 10/12 Fr was passed over the working guide wire. RIRS (7.5/9.3 Fr) was introduced into the access sheath. The stones were fragmented using a holmium laser. The mean operating time was 85 mins (45-130 mins). RESULTS: In 52 out of 55 renal units (94.5%), a flexible ureteroscope could be passed successfully into the kidney through an access sheath. In 3 of the cases (5.4%), the lower ureter could not be dilated. In these patients, the procedure was staged after passing a 6/26 JJ stent. An X-ray KUB was done at the 3-month follow-up visit. A total of 50 renal units (94.3%) were stone free at the 3-month follow-up visit. CONCLUSION: In a majority of the cases, RIRS could be accomplished successfully during the first sitting. Single stage RIRS did not alter the subsequent stone clearance or increase the incidence of morbidity or complications.

Occurrence of pathogenic fungi in soil of burrows of rats and of other sites in bamboo plantations in India and Nepal.

This study examined 215 samples of soil from burrows of rats, other sites in bamboo plantations in different parts of India and Nepal by dilution plating and mouse passage technique for occurrence of Penicillium marneffei and other pathogenic fungi. None of the samples including 25 collected from the burrows of a bamboo rat (Cannomys badius) known to be a carrier of P. marneffei, was positive for the fungus. Among the pathogenic fungi recovered were four isolates of Pseudallescheria boydii (including one from Nepal), two of Trichosporon asteroides, one of Scytalidium hyalinum, 23 isolates of Trichophyton mentagrophytes var. mentagrophytes (including two from Nepal), and two of Microsporum gypseum. Fourteen of the 23 isolates of T. mentagrophytes var. mentagrophytes when tested with the mating types of Arthroderma vanbreuseghemii were found to be of the '+' mating type. The frequent recovery of this dermatophyte from soils of bamboo plantations in several parts of India is remarkable. The study also demonstrates for the first time the occurrence of P. boydii and T. mentagrophytes var. mentagrophytes in Nepalese soil. Among the other fungi recovered were several isolates of species of Aspergillus, Penicillium, Paecilomyces, Fusarium, Chrysosporium, Acremonium, Rhizopus, Mucor, Geotrichum, Trichosporon and Rhodotorula.

Blastomycosis in a South Indian patient after visiting an endemic area in USA.

We describe a case of blastomycosis in a diabetic patient from South India who had visited Milwaukee, Wisconsin, an endemic area for blastomycosis in the USA. After his return to Bangalore, India, the patient developed intermittent fever of moderate to high grade, cough, loss of weight and appetite, and abscesses in the left cubital fossa and thigh regions. Systemic examination at our hospital revealed that he had dullness to percussion over the chest region and decreased breath sounds. Direct examination of Gram-stained smears of the pus from an abscess showed many broad-based budding yeast cells and culture yielded a dimorphic fungus later identified as Blastomyces dermatitidis. Histologic examination of the curettage tissue slides stained with hematoxylin and eosin, periodic acid Schiff's reagent, and Gomori's methenamine silver stain procedures showed many broad-based budding cells characteristic of B. dermatitidis. The patient was successfully treated, initially with amphotericin B, followed by oral itraconazole for a period of 6 months. Blastomycosis cases in India are reviewed and the likely source of infection in this patient is discussed.

Phaeoacremonium krajdenii, a cause of white grain eumycetoma.

We describe the first case of white grain pedal eumycetoma caused by Phaeoacremonium krajdenii in a 41-year-old man from Goa, India. Based on histological examination of biopsy tissue showing serpentine granules, a culture of the granules yielding phaeoid fungal colonies, and morphological characteristics and sequence comparison of the partial beta-tubulin gene with the ex-type isolate of P. krajdenii, the causal agent was identified as P. krajdenii.

Aspergillus endocarditis presenting as femoral artery embolism.

Fungal valvular endocarditis is an unusual cause of endocarditis, yet very important because of its historically poor prognosis. We report two fatal cases of fungal valvular endocarditis following cardiovascular surgery, presenting as femoral artery embolism. Aspergillus terreus and A. flavus were the causative agents of endocarditis in the two patients. Diagnosis was established very early by culture of the emboli and was confirmed later by isolation of the same Aspergillus species from the resected valve tissue.

Subcutaneous phaeohyphomycotic abscess caused by Pleurophomopsis lignicola.

A 41-year-old man with a past medical history of diabetes mellitus type II, AIDS (diagnosed 2 years earlier; CD4 count < 10), peripheral neuropathy, and pulmonary tuberculosis of 2 years duration was admitted to the hospital with abnormal liver function tests. There was a chronic hepatitis/cholestasis that had worsened while the patient was undergoing directly observed tuberculosis therapy. On admission, the patient complained of a painful swelling on his right arm. In the posterior aspect of the arm, there was a 3-4-cm subcutaneous mass that was fluctuant, mobile and tender. Incision of the mass released yellowish pus mixed with blood. Direct examination of the pus in KOH mounts and Gram-stained smears revealed subhyaline, septate, branched hyphae. When the pus was cultured on Sabouraud dextrose agar containing chloramphenicol, several velvety, olivaceous grey colonies grew after 7 days at 25 degrees C. When grown on oatmeal agar, the fungus produced subglobose, rostrate pycnidia with phialidic conidiogenous cells, and 1-celled cylindrical conidia. It was identified as Pleurophomopsis lignicola Petrak. This report describes the third known case of subcutaneous infection caused by P. lignicola in an immunocompromized patient.

Subcutaneous phaeohyphomycosis caused by Veronaea botryosa in the People's Republic of China.

The second case of phaeohyphomycosis caused by Veronaea botryosa in China, in a 12-year-old boy from Jiangsu Province, is presented. Based on direct examination of the scrapings from crusted lesions; histologic examination of the biopsy tissue showing septate, phaeoid hyphal elements; and the culture exhibiting sympodial, conidiogenous cells producing predominantly two-celled, cylindric conidia, the etiologic agent was identified as V. botryosa.

Coccidioidomycosis in India: report of a second imported case.

We describe a fatal case of imported coccidioidomycosis in India in a 22-year-old male who worked in Tucson, Arizona, approximately four years prior to his illness. The diagnosis was based on the presence of characteristic spherules with endospores in biopsy tissue of lymph nodes, bone and pus from a chronic discharging sinus in the left gluteal region and isolation of Coccidioides immitis in culture. C. immitis is one of the most infectious and virulent fungal pathogens and poses a serious occupational hazard for laboratory personnel, especially in areas where the disease is not endemic. To reduce the role of laboratory-acquired infection, all procedures that involve manipulation of cultures of C. immitis should, whenever possible, be conducted in a biological safety cabinet.

Invasive aspergillosis outbreak on a hematology-oncology ward.

An outbreak of invasive aspergillosis occurred in a community hospital in temporal association with construction activity. Epidemiological investigation showed that patients who are at highest risk comprise a small group and are readily identifiable. Clinicians should strive to protect these patients, following guidelines published by the Centers for Disease Control and Prevention.

White grain mycetoma caused by a Cylindrocarpon sp. in India.

We describe a case of white grain eumycetoma of the foot of an Indian male caused by a slow-growing, poorly sporulating fungus that does not match any known agent of this infection. Histologic examination of a biopsy tissue specimen showed oval, lobular, white granules composed of hyaline, septate hyphae, and thick-walled chlamydospores. Culture of granules from a draining sinus yielded compact, very-slow-growing, poorly sporulating colonies producing a strong reddish brown pigment that diffused into the medium. The fungus was identified as a Cylindrocarpon sp. based on the development of rare cylindrical conidia borne from solitary phialides lacking collarettes, in addition to chlamydospores formed singly or in short chains.

Report of the first human case of lobomycosis in the United States.

We describe the first human case of lobomycosis caused by Lacazia loboi in a 42-year-old white male resident of Georgia. The patient had traveled to Venezuela 7 years earlier, where he had planned to rappel down Angel Falls in Canaima. Although he never actually rappelled the falls, he did walk under the falls at least three times, exposing himself to the high water pressures of the falls. He noticed a small pustule with surrounding erythema developing on the skin of his right chest wall. The lesion gradually increased in size and had an appearance of a keloid. For cosmetic reasons, the patient sought medical treatment to remove the lesion. After an uncomplicated excision of the lesion, the patient recovered completely. The excised tissue was fixed in formalin for pathologic examination. Tissue sections stained by hematoxylin and eosin, periodic acid-Schiff stain, and Gomori methenamine silver stain procedures showed numerous histiocytes, multinucleated giant cells, and numerous globose or subglobose, lemon-shaped cells producing multiple blastoconidia connected by narrow tube-like connectors and catenate chains of various lengths characteristic of L. loboi.

Rapid identification of Candida dubliniensis with commercial yeast identification systems.

Candida dubliniensis is a newly described species that is closely related phylogenetically to Candida albicans and that is commonly associated with oral candidiasis in human immunodeficiency virus-positive patients. Several recent studies have attempted to elucidate phenotypic and genotypic characteristics of use in separating the two species. However, results obtained with simple phenotypic tests were too variable and tests that provided more definitive data were too complex for routine use in the clinical laboratory setting. The objective of this study was to determine if reproducible identification of C. dubliniensis could be obtained with commercial identification kits. The substrate reactivity profiles of 80 C. dubliniensis isolates were obtained by using the API 20C AUX, ID 32 C, RapID Yeast Plus, VITEK YBC, and VITEK 2 ID-YST systems. The percentages of C. dubliniensis isolates capable of assimilating or hydrolyzing each substrate were compared with the percentages from the C. albicans profiles in each kit's database, and the results were expressed as percent C. dubliniensis and percent C. albicans. Any substrate that showed >50% difference in reactivity was considered useful in differentiating the species. In addition, assimilation of methyl-alpha-D-glucoside (MDG), D-trehalose (TRE), and D-xylose (XYL) by the same isolates was investigated by the traditional procedure of Wickerham and Burton (L. J. Wickerham and K. A. Burton, J. Bacteriol. 56:363-371, 1948). At 48 h (the time recommended by the manufacturer for its new database), we found that the assimilation of four carbohydrates in the API 20C AUX system could be used to distinguish the species, i.e., glycerol (GLY; 88 and 14%), XYL (0 and 88%), MDG (0 and 85%), and TRE (15 and 97%). Similarly, results with the ID 32 C system at 48 h showed that XYL (0 and 98%), MDG (0 and 98%), lactate (LAT; 0 and 96%), and TRE (30 and 96%) could be used to separate the two species. Phosphatase (PHS; 9 and 76%) and alpha-D-glucosidase (23 and 94%) proved to be the most useful for separation of the species in the RapID Yeast Plus system. While at 24 h the profiles obtained with the VITEK YBC system showed that MDG (10 and 95%), XYL (0 and 95%), and GLY (26 and 80%) could be used to separate the two species, at 48 h only XYL (6 and 95%) could be used to separate the two species. The most useful substrates in the VITEK 2 ID-YST system were TRE (1 and 89%), MDG (1 and 99%), LAT (4 and 98%), and PHS (83 and 1%). While the latter kit was not yet commercially available at the time of the study, it would appear to be the most valuable for the identification of C. dubliniensis. Although assimilation of MDG, TRE, and XYL proved to be the most useful for species differentiation by the majority of commercial systems, the results with these carbohydrates by the Wickerham and Burton procedure were essentially the same for both species, albeit following protracted incubation. Thus, it is the rapidity of the assimilation achieved with the commercial systems that allows the differentiation of C. dubliniensis from C. albicans.