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.

Effect of Combined Therapy Using Diode Laser and Photodynamic Therapy on Levels of IL-17 in Gingival Crevicular Fluid in Patients With Chronic Periodontitis

Introduction: The aim of this study was to evaluate the efficacy of combination therapy of diode laser and photodynamic therapy (PDT) as an adjunct to scaling and root planing (SRP) on interleukin-17 (IL-17) levels in gingival crevicular fluid (GCF) in patients with chronic periodontitis. Methods: Thirty subjects with chronic periodontitis were included. All teeth received periodontal treatment comprising of SRP. Using a split mouth study design, the test group was additionally treated with a combination therapy of diode laser and PDT. GCF was collected to evaluate IL-17 levels at baseline and 3 months. Results: There was no difference in baseline values for levels of IL-17 in GCF in the test group and the control group. A significant decrease in GCF levels of IL-17 was observed in both treatment groups 3 months after treatment (P < 0.001). However, the treatment groups showed no significant difference (P > 0.05). Conclusion: Based on the results of the present study it was concluded that, GCF levels of IL-17 changed significantly after treatment regardless of treatment modality.

Inhibition of Tongue Coat and Dental Plaque Formation by Stabilized Chlorine Dioxide Vs Chlorhexidine Mouthrinse: A Randomized, Triple Blinded Study

BACKGROUND

Chlorine dioxide (ClO2) is an oxidizing agent with known bactericidal, viricidal and fungicidal properties. Its efficacy in reducing the halitosis has been established by previous literature. However, data evaluating its antiplaque property is scarce. Chlorhexidine (CHX) is considered as the gold standard and an effective adjunctive to mechanical plaque removal. However, it is associated with few reversible side effects. Therefore a study was conducted to assess the antiplaque property of ClO2 containing mouthrinse against CHX mouthrinse.

AIMS AND OBJECTIVES

To evaluate the efficacy of stabilized chlorine dioxide containing mouthrinse and CHX containing mouthrinse in inhibition of tongue coat accumulation and dental plaque formation using a four day plaque regrowth model clinically and microbiologically in a healthy dental cohort.

MATERIALS AND METHODS

A Single Center, Randomized, Triple blinded, Microbiological clinical trial was conducted involving 25 healthy dental students volunteers (11 males, 14 females). Two commercially available mouthrinse: Mouthrinse A - Aqueous based ClO2 mouthrinse Freshchlor(®) and Mouthrinse B - Aqueous based 0.2% CHX mouthrinse Hexidine(®) were selected as the test products. Subjects were asked to rinse and gargle for 1 minute with the allocated mouthrinse under supervision after supragingival scaling, polishing and tongue coat removal. After four hours, smears were taken from the buccal mucosa and tooth surface. On the fifth day from baseline of four day non brushing plaque regrowth model the samples were again taken from buccal mucosa and tooth surface followed by recording of plaque scores by Rastogi Modification of Navy Plaque index, extent of tongue coat by Winkel's tongue coating index and measuring tongue coat wet weight in grams. The samples collected were subjected to microbial analysis and the results were expressed as colony forming units (CFUs) per sample.

STATISTICAL ANALYSIS

The Data was analysed using SPSS 16.00 and presented using descriptive statistics. Independent t-test was used for the comparison between mouthrinse A groups & mouthrinse B group.

RESULTS

The plaque scores and Winkels tongue coat scores, wet tongue coat weight recorded on the fifth day after the use of the two mouthrinse didn't show a statistically significant difference. The CFU per sample from tooth and mucosa after four hours revealed low bacteria count with respect to mouthrinse B however the CFU obtained on the fifth day did not show a statistically significant difference between the two mouthrinse.

CONCLUSION

The clinical antiplaque efficacy of CHX and ClO2 mouthwash is comparable and so is the efficacy in reducing the oral bacterial load.

Gingival Fibromatosis with Distinctive Facies - A Three Generation Case Report

Hereditary gingival fibromatosis (HGF) is a rare disorder characterized by progressive and varying degrees of gingival overgrowth. Oral manifestations may vary from minimal involvement of only tuberosity area and the buccal gingiva around the lower molars to a generalized gingival enlargement. It can occur as an isolated disorder but can be one feature of a syndrome. Although the clinical and histopathological characteristics of HGF are well known and described, the pathogenic mechanism remains unknown. The goal of this article is to describe a family with three generations afflicted with a syndromic form of HGF known as gingival fibromatosis with distinctive facies, and discuss the diagnosis and treatment of the disease.

Oral malignant melanoma: A silent killer?

Oral malignant melanomas are extremely rare lesions and occur commonly in the maxillary gingiva more frequently on the palate with fewer incidences in the mandibular gingiva. Though these lesions are biologically aggressive, they often go unnoticed since they are clinically asymptomatic in the early stages and usually present merely as a hyperpigmented patch on the gingival surface. These lesions if diagnosed at an early in situ stage are potentially curable and definitely have a better prognosis, but unfortunately as they are clinically asymptomatic, it results in delayed diagnosis thus making the prognosis extremely poor. This paper presents the case of a patient who visited our department with the complaint of darkened patches on the gums and his concern was purely aesthetic. There were no symptoms associated with the hyperpigmented lesions and hence the patient did not approach us earlier. When the lesions grew larger and were unsightly, the patient has seeked dental advice. Histopathologic investigation confirmed the diagnosis as ‘Oral Malignant Melanoma’. Though aggressive therapy was instilled immediately, unfortunately, the patient succumbed to death within a few months after diagnosis as the lesion was highly invasive. Due to the biologically aggressive but clinically silent nature of progression of the lesion, the importance of maintaining a high index of suspicion and early detection and diagnosis for any pigmented gingival lesions cannot be overemphasised. Diagnosis must be based on thorough detailed history and valid histologic evidence.

Microscope-enhanced periodontal therapy: a review and report of four cases

AIM

The aim of this report is to review the status of the use of surgical microscopes and microsurgery and their clinical application in the field of periodontics.

BACKGROUND

The use of magnification systems and periodontal microsurgery are part of a broad movement in dentistry toward the use of minimally invasive procedures to replace the need for more extensive surgical procedures. While magnification systems are widely used in endodontics, their application in periodontics is still in its nascent phase. However, clinicians have reported that use of magnification facilitates the use of minimal invasive periodontal surgery.

TECHNIQUE

The surgical microscope is an invaluable aid for periodontists in the diagnosis and treatment of periodontal disease. Magnified vision used in conjunction with microsurgical instruments and techniques can lead to a higher quality of care and an improved surgical outcome.

SUMMARY

Surgical operating microscopes have shown promising results in the hands of periodontists who are properly trained in their use. Despite the apparent advantages, there is still a lack of "high level of evidence" in the form of controlled clinical trials to estimate the magnitude of the real benefits of the microsurgical approach over the conventional approach.

CONCLUSION

The scientific community understands the need for more investigations to completely understand the conditions that would best favor the creation of a tooth substitute. Recent gains in the understanding of the molecular regulation of tooth morphogenesis, stem cell biology, and biotechnology offers the opportunity to realize this goal.

CLINICAL SIGNIFICANCE

Even though all the procedures shown in this review can be performed using normal vision, performing these procedures using a surgical microscope and microsurgical instruments offers definite advantages in terms of improved visual acuity, superior approximation of wounds, rapid wound healing, decreased post-operative morbidity, and increased acceptance by the patients.

Outbreak of sporotrichosis among tree nursery workers

In spring 1994, an outbreak of sporotrichosis occurred at a tree nursery in Florida; 9 (14%) of 65 workers involved in production of sphagnum moss topiaries developed lymphocutaneous sporotrichosis. A cohort study of all 65 employees was conducted to identify risk factors for sporotrichosis, and an environmental investigation was done. The risk of sporotrichosis increased significantly with the duration of working with sphagnum moss (P < .05), in particular with filling topiaries (P < .05), and with having less gardening experience (P < .05). Wearing gloves was protective (P < .005). Sporothrix schenckii was cultured from patients and sphagnum moss used in topiary production. Use of restriction fragment length polymorphism revealed an identical pattern for patient isolates that was different from the patterns of environmental isolates. Physicians should be aware of sporotrichosis in patients with ulcerative skin lesions who have a history of occupational or recreational exposure to sphagnum moss.

Acremonium kiliense endophthalmitis that occurred after cataract extraction in an ambulatory surgical center and was traced to an environmental reservoir

During October and November 1993, four patients contracted Acremonium kiliense endophthalmitis at one ambulatory surgical center. We hypothesized that the source was environmental and conducted a matched case-control study, environmental evaluation, and observational studies. Case and control patients were similar in clinical characteristics. However, case patients all had surgery on the first operative day of the week or had surgery significantly sooner after the operating room opened than did controls (a median of 46 vs. 150 minutes afterward; P = .03). An environmental review revealed the ventilation system was switched on 5-30 minutes before procedures began on the first operative day of the week, and air was filtered before but not after humidification. Cultures of the humidifier water in the ventilation system yielded A. kiliense phenotypically identical to isolates from case patients. Our data suggest that switching on the ventilation system each week aerosolized a reservoir of A. kiliense and caused infection of patients. We believe this is the first reported outbreak of fungal endophthalmitis traced to an environmental source, and it underscores the importance of utilizing established hospital infection control practices in the outpatient setting.

Zygomycosis of the maxillary sinus and palate caused by Basidiobolus haptosporus

Basidiobolus haptosporus is known to cause subcutaneous zygomycosis in tropical Africa and Asia. We cared for a 49-year-old hyperglycemic, asplenic man who had never traveled outside the United States and who was seen initially for a painless palatal ulcer with cutaneous hypesthesia of the right cheek and upper lip. An invasive process involved the right middle nasal turbinate, maxillary antrum, maxillary division of the trigeminal nerve, and bony palate. Histological examination of biopsy tissue showed necrotizing granulomata with broad, nonseptate hyphae. Basidiobolus haptosporus was cultured from this tissue. Various laboratory studies revealed no immunologic defect and his lesions responded to therapy with amphotericin B. To our knowledge, this represents the first case of zygomycosis caused by B haptosporus in the Americas and the first culture-documented case of invasive mycosis caused by this mold.

Occurrence of Histoplasma capsulatum Darling, 1906 in Israel, with a review of the current status of histoplasmosis in the Middle East

The isolation of Histoplasma capsulatum from a bat cave in the Galilee region of Israel is reported along with the discovery of a bat (Myotis myotis) infected by H. capsulatum. Soils collected in avian and chiropteran habitats throughout Israel also yielded the following fungi of medical interest: Arthroderma quadrifidum, A. tuberculatum, Candida parapsilosis, Chrysosporium indicum, C. keratinophilum, C. tropicum, Cryptococcus neoformans, Ctenomyces serratus, Microsporum gypseum, and Petriellidium boydii. All available reports concerning the occurrence of H. capsulatum and histoplasmosis in the Middle East are critically reviewed.

First European report of swine infection by Microsporum nanum

The first European case of swine infection by Microsporum nanum is reported. The infected pig came from a farm in the Emilia-Romagna region of Italy. European records of human and lower animal infections by this fungus and soil isolation records are discussed.