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A novel nanowire sensor is developed for full characterization of polarization states of radiation in terahertz time-domain spectroscopy, offering a fast, accurate and convenient platform to allow studying the anisotropic complex dielectric properties of materials.

The introduction of ustekinumab, an interleukin [IL]12/23 p40 inhibitor, to the therapeutic armamentarium of Crohn's disease has provided a much needed treatment option for patients who have failed conventional biologics with anti-tumour necrosis factor [TNF] and anti-integrin agents. Despite targeting two major cytokine pathways, the side effect profile of ustekinumab appears to be favourable in clinical trials. In particular, the risk of tuberculosis infection was observed to be lower than in patients who have received anti-TNF agents. The risk of non-tuberculosis mycobacterium infection, however, remains unknown. Here, we report the first case of a patient with Crohn's disease who developed Mycobacterium abscessus infection while on ustekinumab treatment.

The usability and tunability of the essential InP-InGaAs material combination in nanowire-based quantum wells (QWs) are assessed. The wurtzite phase core-multi-shell InP-InGaAs-InP nanowire QWs are characterised using cross-section transmission electron microscopy and photoluminescence measurements. The InP-InGaAs direct interface is found to be sharp while the InGaAs-InP inverted interface is more diffused, in agreement with their planar counterpart. Bright emission is observed from the single nanowires containing the QWs at room temperature, with no emission from the InP core or outer barrier. The tunability of the QW emission wavelength in the 1.3-1.55 μm communication wavelength range is demonstrated by varying the QW thickness and in the 1.3 μm range by varying the composition. The experiments are supported by simulation of the emission wavelength of the wurtzite phase InP-InGaAs QWs in the thickness range considered. The radial heterostructure is further extended to design multiple QWs with bright emission, therefore establishing the capability of this material system for nanowire based optical devices for communication applications.

We compare the electronic characteristics of nanowire field-effect transistors made using single pure wurtzite and pure zincblende InAs nanowires with nominally identical diameter. We compare the transfer characteristics and field-effect mobility versus temperature for these devices to better understand how differences in InAs phase govern the electronic properties of nanowire transistors.

We have developed a terahertz radiation detector that measures both the amplitude and polarization of the electric field as a function of time. The device is a three-contact photoconductive receiver designed so that two orthogonal electric-field components of an arbitrary polarized electromagnetic wave may be detected simultaneously. The detector was fabricated on Fe+ ion-implanted InP. Polarization-sensitive detection is demonstrated with an extinction ratio better than 100:1. This type of device will have immediate application in studies of birefringent and optically active materials in the far-infrared region of the spectrum., 3 pages, 3 figures

Globalization has led to a rapid influx of female workers from Asian countries with high prevalence of HIV to Singapore, with many entering the entertainment industry. We assessed the prevalence of sexual services, condom use, and self-initiated screening for sexually transmitted infections (STIs) and associated variables among foreign female entertainment workers in Singapore. A cross-sectional survey of 317 female entertainment workers, using mystery clients, was conducted on a two-stage proportional cluster sample of 93 entertainment establishments stratified by geographical zone in Singapore. We found a high prevalence (71 %) of sexual services in entertainment establishments with 53 % of the female entertainment workers reporting selling sex. Consistent condom use for sex with paying clients in a usual week in the past 3 months was low, ranging from 37.9 % for oral sex, 46.9 % for anal sex, to 51.9 % for vaginal sex. On multivariate logistic regression, consistent condom use for vaginal sex with clients showed a significant independent association with the entertainment worker’s behavior of asking clients to use condoms and a borderline association with entertainment worker being a Chinese national. Less than half (48.9 %) of the sex workers had ever been screened for STIs either locally or in their home country. The only independent factor significantly associated with STI screening was having to support one’s family. In summary, a high percentage of foreign female entertainment workers in Singapore reported selling sex. Condom use and STI screening were low among them. Access to STI screening, treatment, and education services should be enhanced for foreign female entertainment workers in Singapore.

Background and study aims Endoscopic spray cryoablation is a novel approach for the treatment of Barrett's esophagus. However, few studies have reported its efficacy, especially with the use of carbon dioxide (CO (2)). The aim of the current study was to evaluate the short term efficacy and complications using CO (2) in endoscopic cryoablation of Barrett's esophagus. Methods Patients diagnosed with Barrett's esophagus underwent monthly stepwise cryoablation with pressurized CO (2) gas, with follow-up esophageal biopsies until complete histological reversal was achieved. Responses were analyzed with an intention-to-treat analysis according to complete response for intestinal metaplasia (CR-IM), which was defined as the elimination of all intestinal metaplasia including specialized intestinal metaplasia (SIM), subsquamous SIM, and dysplasia with intestinal metaplasia in the biopsies under narrow-band imaging (NBI). Results In total, 22 patients were enrolled, 20 of whom completed the treatment. Two patients declined further ablation after the first cryotherapy session. A total of 44 sessions were performed; a median of 2 sessions per patient (range 1 - 3 sessions) were needed to complete the ablation of Barrett's esophagus. No severe complications occurred. Follow-up endoscopies were performed in 20 patients (90.9 %). Two patients (9.1 %) were lost to follow-up. Median follow-up was 10 months (range 6 - 18 months). After cryotherapy, 20 patients (90.9 %) reached CR-IM of Barrett's esophagus. Patients underwent a median number of 3 follow-up endoscopies (range 2 - 4) with biopsies. At 6 months, recurrence was evident in three patients (13.6 % of the overall population, 15.0 % of the CR-IM population). One of the three patients developed intestinal metaplasia but no dysplastic change and the other two developed subsquamous SIM. Conclusions The pressurized CO (2) spray cryotherapy is a relatively effective and safe endoscopic treatment for Barrett's esophagus.

This paper considers the form of monetary policy coordination and regional exchange rate arrangement that would best support economic and financial integration in East Asia. In view of the region's economic diversity, we propose a graduated program of informal policy cooperation from weak forms of cooperation to more intensive modes of cooperation such as the adoption of common monetary policy objectives. An array of informal monetary arrangements rooted to the degree of institutional development can improve the effectiveness of both sovereign and regional institutions, and promote integration in East Asia. Drawing upon the European experience with the Exchange Rate Mechanism (ERM), we conclude that East Asia should first embark on other forms of integration to aid in the development of a high degree of real and nominal convergence amongst the regional countries. Only then would an ERM-type system that employs a regional monetary unit become more sustainable and less susceptible to speculative currency attacks in the region.

Summary Background There are few studies on the prevalence of acne vulgaris among Asian teenagers. Objectives To determine the epidemiology of acne in teenagers in Singapore. Methods A community-based cross-sectional study in 1045 adolescents aged 13–19 years. Results Of these respondents, 88% identified themselves as having acne. Eight hundred and six of these respondents were examined by a dermatologist, and 51·4% were classified as having mild acne, 40% moderate acne and 8·6% severe acne. Isolation of Propionibacterium acnes was attempted in 262 subjects. Cultures were positive in 174 subjects, giving an isolation rate of 66·4%. Antibiotic-resistant strains of P. acnes were detected in 26 isolates (14·9%). Eleven of these 26 subjects (42%) had previously been treated or were presently on antibiotic treatment for acne, but the other 58% of students who had antibiotic-resistant strains of P. acnes did not give a history of prior antibiotic therapy. Teenagers expressed psychological distress over acne, and believed that hormonal factors, diet and hygiene were important factors in causing acne. Conclusions There is a need for accessible, accurate education on acne and its appropriate treatment.

The use of tetracycline antibiotics in the treatment of acne is long established in dermatology, with a proven record of both safety and efficacy. Minocycline is a drug that is generally considered the most effective of the tetracycline derivatives. This article is a brief review of the use of minocycline in acne and its new extended-release version for the treatment of moderate-to-severe acne vulgaris. Prior to the introduction of this new formulation of minocycline, it had been available as immediate- and modified-release formulations. The main advantage of this new extended-release formulation is the lower incidence of vestibular side effects; however, presently, there are no trials comparing the efficacy of this formulation to other formulations of minocycline in the treatment of acne.

Viral skin infections are common findings in organ transplant recipients. The most important etiological agents are the group of human herpesviruses (HHV), human papillomaviruses (HPV), and molluscum contagiosum virus. HHV that are important in this group of patients are herpes simplex virus (HSV) types 1 and 2, varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), HHV-6 and -7, and HHV-8, which causes Kaposi sarcoma (KS). HSV infections are characterized by their ability to establish latency and then reactivate at a later date. The most common manifestations of HSV infection in organ transplant recipients are mucocutaneous lesions of the oropharynx or genital regions. Treatment is usually with acyclovir, valaciclovir, or famciclovir. Acyclovir resistance may arise although the majority of acyclovir-resistant strains have been isolated from AIDS patients and not organ transplant recipients. In such cases, alternatives such as foscarnet, cidofovir, or trifluridine may have to be considered. VZV causes chickenpox as well as herpes zoster. In organ transplant recipients, recurrent herpes zoster can occur. Acute chickenpox in organ transplant patients should be treated with intravenous acyclovir. CMV infection occurs in 20-60% of all transplant recipients. Cutaneous manifestations, which include nonspecific macular rashes, ulcers, purpuric eruptions, and vesiculobullous lesions, are seen in 10-20% of patients with systemic infection and signify a poor prognosis. The present gold standard for treatment is ganciclovir, but newer drugs such as valganciclovir appear promising. EBV is responsible for some cases of post-transplant lymphoproliferative disorder, which represents the greatest risk of serious EBV disease in transplant recipients. HHV-6 and HHV-7 are two relatively newly discovered viruses and, at present, the body of information concerning these two agents is still fairly limited. KS is caused by HHV-8, which is the most recently discovered lymphotrophic HHV. Iatrogenic KS is seen in solid-organ transplant recipients, with a prevalence of 0.5-5% depending on the patient's country of origin. HPV is ubiquitous, and organ transplant recipients may never totally clear HPV infections, which are the most frequently recurring infections in renal transplant recipients. HPV infection in transplant recipients is important because of its link to the development of certain skin cancers, in particular, squamous cell carcinoma. Regular surveillance, sun avoidance, and patient education are important aspects of the management strategy.

Atomic scale computer simulation is used to predict the energies and structures associated with surface hydroxide groups on the (1 0 0), (1 1 0) and (1 1 1) surfaces of UO 2 and PuO 2 . The (1 0 0) surface is of particular interest since it is dipolar and therefore must be stabilised by a series of surface defects. Two different (1 0 0) defect terminations are considered, one a conventional series of surface layer defects, the other a partial reconstruction with (1 1 1) like facets. The latter is the most stable termination in the absence of hydroxide. In the presence of hydroxide this preference is reversed.

Sarcoidosis is a systemic noncaseating granulomatous disorder of unknown origin involving multiple organ systems. There has been no report so far to describe the epidemiological pattern of cutaneous involvement in sarcoidosis in South-East Asia with diverse ethnic groups. A retrospective study examining the clinicopathological features of all patients diagnosed with sarcoidosis at a tertiary dermatology centre in Singapore from 1980 to 2003 was conducted. Cutaneous sarcoidosis was diagnosed in 25 patients: 13 were Indian, 11 were Chinese and one was Eurasian. Cutaneous manifestations included papules, nodules, plaques and scarring alopecia. Extracutaneous involvement of lymph nodes (four patients), lungs (eight patients) and eyes (two patients) was seen. Eight patients had abnormal chest radiographic findings. Histopathological examination of skin lesions revealed noncaseating, epithelioid granulomatous infiltration in the dermis without evidence of mycobacterial infection, deep fungal infection or polarizable birefringent material. Treatment modalities included corticosteroids, hydroxychloroquine, isotretinoin, methotrexate and surgical excision. Five patients had complete resolution of the cutaneous lesions. Cutaneous sarcoidosis is rare in Asia and indeed in Singapore. Extracutaneous involvement is not uncommon and a thorough clinical evaluation should be undertaken.

This brief review focuses on defect and microstructural issues of importance for applications of ion irradiation of semiconductors. Ion irradiation of semiconductors can lead to a variety of disordering behaviour that depends not only on the semiconductor material but also on implantation parameters such as ion fluence, flux, energy and mass as well as the implantation temperature. In some cases, such as silicon implanted at or below room temperature, ion disorder leads readily to amorphization, whereas some other semiconductors, such as aluminium arsenide and gallium nitride, undergo very efficient dynamics annealing even at liquid nitrogen implantation temperatures and are difficult or even impossible to amorphize. In cases of efficient dynamic annealing a rich array of defects can result during implantation. This presentation gives examples of the defect structures that can arise during implantation and subsequent annealing of semiconductors and illustrates how disorder can be exploited to advantage in both electronic and optoelectronic device applications. In particular, open volume defects such as voids and cavities can be generated in silicon and these can be used to selectively remove metal impurities. In compound semiconductors such as zinc oxide, ion irradiation can be used to introduce defects that raise the resistivity of the material by more than seven orders of magnitude. Finally, disorder can be used to promote intermixing of the elemental constituents in adjacent multi-layer compound semiconductors and this process has been used to tune the wavelength of lasers.

Microwaveable acrylic denture resins are believed to provide an effective means of repairing fractured dentures. This in vitro investigation compared the bond strength of a microwaveable acrylic resin as a denture repair material to two established auto-polymerized resins. Fifty-one specimens were made using Lucitone 199 as a simulated denture base, and were then divided into three groups of 17 samples each. Each test group was bonded with the following acrylic resins: Acron Mc, Rapid Repair and Palapress. A shear bond strength test was carried out 24 h after the samples were bonded. Fracture analysis showed that bond failure was adhesive for all groups. Shear bond values showed a statistically significant difference at P < 0.05 level between Acron Mc and Rapid Repair; Palapress and Rapid Repair, and indicated that Acron Mc and Palapress were superior to Rapid Repair as a repair material. However, there was no statistical difference found between Acron Mc and Palapress. Microwaveable acrylic resins produce repaired junctions of adequate strength.

We have studied the photoluminescence properties of as-grown GaAs1−xNx epitaxial layers grown on GaAs containing 0.6%, 1.77%, and 2.8% nitrogen. We found laser emission from thick (d>200 nm) GaAs0.972N0.028 layers exhibiting the characteristic lasing properties of random lasers. This is unusual because random lasers have so far only been associated with highly disordered or random media. We believe that high gain in combination with structural inhomogeneities that are evident in these GaAs0.972N0.028 layers, can explain the random lasing in such epitaxial layers.

Acne vulgaris is a very common disorder, affecting virtually every adolescent at some point in time. Systemic antibacterials have been used in the treatment of acne for many years, and there are several commonly used antibacterials which have established efficacy and safety records. In recent years, the issue of antibacterials resistance has become more prominent, especially with concerns that Propionibacterium acnes can transfer antibacterials resistance to other bacteria within the resident skin flora. Commonly used antibacterials include tetracycline, doxycycline, minocycline, erythromycin (and other macrolides) and trimethoprim/sulfamethoxazole (cotrimoxazole). The choice of antibacterial should take into account efficacy, cost-effectiveness, benefit-risk ratios, patient acceptability and the potential for the development of resistance. Poor clinical response can be the result of poor compliance, inadequate duration of therapy, development of gram-negative folliculitis, resistance of P. acnes to the antibacterial(s) administered, or a high sebum excretion rate. In order to help prevent the development of resistance a number of measures should be undertaken: antibacterials are prescribed for an average of 6 months; if retreatment is required, utilize the same antibacterial; generally, antibacterials should be given for at least 2 months before considering switching due to poor therapeutic response; concomitant use of oral and topical chemically-dissimilar antibacterials should be avoided (try benzoyl peroxide and/or retinoids instead) and systemic isotretinoin should be considered if several antibacterials have been tried without success.

To examine whether or not the combination of diclofenac suppository with peri-prostatic nerve block (PPNB) was effective in reducing the degree of pain experienced during transrectal ultrasound (TRUS)-guided prostate biopsy in a randomised single-blind placebo-controlled trial.In all, 96 patients having a planned TRUS-guided prostate biopsy were randomised into one of the following arms on a 1:1 basis: 10 mL 1% lignocaine PPNB and placebo suppository (control) or 10 mL 1% lignocaine PPNB and 100 mg diclofenac suppository (treatment). Pain scores were recorded using the Numerical Rating Scale for pain (0-10) at the following time-points: (i) introduction of probe, (ii) during biopsy, (iii) 1 h after biopsy, (iv) later that evening (≈6 h after biopsy) and (v) 1 day after biopsy. Patients were asked about their preferred method for pain control if a repeat TRUS-guided prostate biopsy was required: local anaesthetic (LA) again or intravenous sedation.There were no significant differences in age (P = 0.653) or PSA level (P = 0.584) between either study arm. The differences in pain scores between the control and treatment groups were not significant at Time 1 (probe insertion; P = 0.299), Time 2 (biopsy; P = 0.983), Time 4 (evening after; P = 0.231) and Time 5 (1 day after biopsy; P = 0.384). At Time 3 (1 h after biopsy), the control pain scale scores were statistically significantly higher than the treatment pain scale scores (P = 0.044). There was no difference between treatment (87%) and control (80%) groups as to whether they would prefer to repeat the biopsy under LA (P = 0.373).The use of a diclofenac suppository with PPNB did not show any clinically meaningful effect in decreasing pain or improving tolerability of TRUS-guided prostate biopsy and is not recommended. PPNB TRUS-guided biopsy is extremely well tolerated, with80% of patients electing for subsequent LA biopsy if required.

A pseudomorphic Al0.5Ga0.5As/In0.25Ga0.75As/GaAs asymmetric quantum wire (QWR) structure was grown on GaAs V-grooved substrate by low pressure metal organic vapor phase epitaxy. The formation of crescent shaped QWRs at the bottom of the V-grooves was confirmed by both transmission electron microscopy and photoluminescence (PL) spectra. The temperature dependence of PL spectra demonstrated a fast decrease of the sidewall quantum well PL intensity with increasing temperature, which originates from relaxation of carriers from well to wire region. The self-aligned dual implantation technique was successfully used to selectively disable the adjacent quantum structures. Decrease of the PL intensity of QWR at 8 K was observed after selective implantation, which resulted from a decreased number of carriers relaxed from adjacent quantum structures.

Polyaniline base films with varying degrees of crosslinking were cast from N-methylpyrrolidinone solutions at different processing temperatures. The effects of crosslinking on the films' physical properties (solubility, surface morphology, tensile strength), doping characteristics, and transport of ions across the films were investigated. The presence of crosslinking in the film significantly decreases its solubility and enhances its strength, but a comparison of the surface anion/N ratio (as determined by X-ray photoelectron spectroscopy) and the bulk anion/N ratio (as determined from elemental analysis) shows that uniform doping of the crosslinked film by acids is much more difficult to achieve. The transport of H + ions through the base film is characterized by an initial time lag followed by a steady-state flux. Both of these parameters are dependent on the degree of crosslinking in the film. It appears that doping of the base film and transport of ions across a doped film are affected differently by crosslinking in the film.

We report a case of atypical pityriasis rosea in a 24-year-old Malay man. He presented with an 11-month history of three recurrent and persistent episodes of pityriasis rosea associated with oral ulcers. The first episode lasted for one month and recurred within 14 days. The second episode lasted for three months and recurred within nine days. The third episode lasted for seven months. Although all three episodes were not preceded by any prodromal symptoms, a herald patch was noted on three different sites (the left iliac fossa, abdomen and chest) on each successive episode. Recurrent pityriasis rosea and its association with oral ulcers, although quite uncommon, have been reported in the literature. However, reports of multiple recurrences, with prolonged duration of each episode and very short remissions in between, have not been made. To the best of our knowledge, this is the first report of such unique presentation.

BackgroundSingapore is a small industrialized island state with a low accident rate and few hazardous chemical-related injuries reported. However, the use of chemicals continues to increase and pose hazards in the workplace.AimsTo study workplace chemical injuries and exposures to improve worksite safety.MethodsWork-related chemical exposure cases were identified from emergency department (ED) computerized records from 2007 to 2010.ResultsA total of 239 cases were identified. Most of the patients were male (92%) and young adults (73% aged between 21 and 40 years). Fifty per cent of the workers were foreign workers. Most of them were cleaners, labourers and technicians (53%) and worked mainly in the construction and manufacturing industries (47%). All the exposures were acute and presented within 4h of the exposure incident (52%). Most of the chemical exposures were to the eye (55%) and skin (32%). The chemicals involved included corrosives (41%), hydrocarbons (18%) and cleaning solutions (9%). Pre-hospital decontamination (eye and skin irrigation) was performed for 54% of the workers. Antidote treatment with calcium gluconate for hydrofluoric acid exposure was used for five patients in the ED. Only 11% of patients were admitted. Four patients had surgical procedures and five patients had long-term complications. Forty-five incidents were notified to the Ministry of Manpower. The under-reporting rate for cases with >3 days of medical leave was 66%.ConclusionsWork-related chemical exposures that present to the ED had low morbidity. Most of the workers did well with immediate decontamination and supportive treatment but antidotes were required for some exposures. Language: en

Of 149 workers from the electronics industry with occupational dermatoses seen at the Joint Occupational Dermatoses Clinic at the National Skin Centre, Singapore, 51.0% (76) were diagnosed to have irritant contact dermatitis, 40.9% (61) had allergic contact dermatitis, and 8.1% (12) had noncontact dermatitis. More than half of the patients were younger than 30 years of age. Common irritants were soldering flux, oils and coolants, solvents, and acids/alkalis. The most common allergens were nickel and resins, followed by rubber chemicals and the constituents of flux. Of the noncontact dermatitis, 8 were caused by occupationally relevent exacerbation of endogenous eczema, whereas there was one case each of miliaria, frictional dermatitis, and fatal toxic epidermal necrolysis caused by trichloroethylene allergy.

Tuberculosis verrucosa cutis (TBVC) is a paucibacillary form of cutaneous tuberculosis caused by exogenous re-infection in previously sensitized individuals. Here, we report an unusual case of TBVC in a 53-year-old Chinese woman that had been present for 44 years and resulted in fixed-flexion deformity of her arm and functional disability. The diagnosis was made by a positive culture for Mycobacterium tuberculosis and she responded well to antituberculous therapy. To our knowledge, this is the first such case of TBVC reported in the English literature with sequelae of functional impairment of the arm.

The application of IT into teaching has become a hot topic in current teaching filed; Benefiting from the development of IT, collaborative learning is involved in many new elements and is forward developed,which provides a new opening to the reform of English teaching. This paper introduces the theories of collaborative learning, and analyzes the necessity of integrating collaborative learning in IT-based environment into English teaching. It aims at exploring the way of English teaching reform in higher vocational schools from the perspective of collaborative learning in IT-based network environment.

Microstructural and optical properties of InAs-inserted and reference single GaAsN/GaAs quantum-well (QW) structures grown by metalorganic chemical vapor deposition were investigated using cross-sectional transmission electron microscopy and photoluminescence (PL). Significant enhancement of PL intensity and a blueshift of PL emission were observed from the InAs-inserted GaAsN/GaAs QW structure, compared with the single GaAsN/GaAs QW structure. Strain compensation and In-induced reduction of N incorporation are suggested to be two major factors affecting the optical properties.

Individuals with AIDS are at higher risk of developing severe cutaneous adverse drug reactions. We report two AIDS patients with drug-induced toxic epidermal necrolysis (TEN). The suspected drugs were discontinued. Both patients were treated with intravenous human immunoglobulins at a dose of 1 g/kg body weight per day for two consecutive days and both experienced a good outcome. Intravenous immunoglobulin potentially lowers the morbidity and mortality of TEN and shortens the duration of the patient's hospitalization.

Proton irradiation was used to create interdiffusion in In0.5Ga0.5As quantum dots (QDs), grown by low-pressure metalorganic chemical vapor deposition. After 25-keV proton irradiation, the QD samples were annealed at two temperatures (700 or 750 °C) for 30 s. It was found that much lower annealing temperatures were needed to recover the photoluminescence signals than in the quantum-well case. Large blueshifts (120 meV) and narrowing of the photoluminescence spectra were seen. Various doses (5×1013–1×1015 cm−2) and implant temperatures (20–200 °C) were used to study the interdiffusion processes in these samples. In QD samples, much lower doses were required to achieve similar energy shifts than reported in quantum-well samples.

Wasp stings can present in various ways, ranging from mild self-limiting illness to severe multi organ failure with a potentially fatal outcome. We report a case of multiple wasp stings leading to acute renal failure needing prolonged dialysis support and posterior reversible encephalopathy syndrome.

Objective To compare gender differences in the factors associated with condom use at most recent voluntary intercourse among heterosexual adolescents attending a public clinic for sexually transmitted infections (STIs). Study design Between 2008 and 2011, we conducted a cross-sectional survey on 964 never-married adolescents between 14 and 19 years of age who reported having engaged in voluntary intercourse for most recent sexual encounter and were attending the only public STI clinic in Singapore for screening or treatment of STIs. Data were collected using a self-administered questionnaire. Results The response rate to the questionnaire was 85.2%. In multivariate analysis, condom use at last intercourse for both genders was negatively associated with Malay race and peer connectedness and was positively associated with confidence in the ability to use a condom correctly. Being employed was positively associated with condom use for female respondents only. For male respondents only, condom use showed a positive association with living in better housing, older age at first intercourse, and engaging in sexual intercourse with commercial sex partners. Almost all (90%) commercial sex partners suggested condom use and provided condoms compared with 8.1% of non–sex worker partners. Condom use showed a negative association with inconvenience in its use among male respondents but not female respondents. Conclusion STI prevention programs for adolescents must promote condom use with nonpaying partners, address barriers to condom use, and develop condom application skills, taking into account gender differences. Future research should explore condom use within dating relationships.

Oral isotretinoin is effective for acne vulgaris but concerns remain regarding its adverse effects.This study aims to evaluate the safety and efficacy of isotretinoin for acne vulgaris in Asian patients.We conducted a 4-year retrospective study on all patients with acne vulgaris treated with isotretinoin, between January 2005 and December 2008 at the National Skin Centre in Singapore. Medical records were reviewed for information on patient demographics, acne severity, isotretinoin dose, duration, adverse effects and outcome.There were 2,255 patients, with a mean age of 22.5 years, male:female ratio of 2.5:1 and 82.3% being Chinese. The mean starting dose of isotretinoin was 0.4 mg/kg and on average, patients received 7.8 months of treatment at a mean dose of 0.5 mg/kg. Mean total cumulative dose was 95.6 mg/kg. Vast majority (93.9%) achieved complete remission or substantial improvement. Thirty-eight (2.2%) and 24 patients (2.7%) developed elevated serum levels of alanine and aspartate aminotransferases subsequent to treatment. There were 194 (12.1%) and 80 (4.8%) patients who developed hyperlipidaemia and hypertriglyceridaemia respectively. Isotretinoin was generally well-tolerated, with 6.4% (n = 145) discontinuing due to side-effects.This study reaffirms the overall safety and efficacy of oral isotretinoin in Asian patients with acne vulgaris.

Rhinoscleroma is a chronic, slowly progressive, inflammatory disease of the upper respiratory tract. It is associated with Klebsiella rhinoscleromatis infection. We present the clinical and pathological features of four patients diagnosed with rhinoscleroma at the National Skin Centre, Singapore between 1997 and 2010. All four patients presented with only cutaneous involvement, and the diagnosis was clinched via histological examination. The patients were treated with a combination of antibiotics. Two patients who were on follow-up at the time of this writing responded positively to the antibiotic treatment, while two were lost to follow-up. Rhinoscleroma is a diagnostic challenge, as it is an uncommon disease in Singapore and Malaysia. We highlight this condition to raise awareness of the disease in order to aid in early diagnosis of patients. Without treatment, this condition can result in significant complications, including involvement of the lower airways. Early diagnosis and appropriate treatment help to reduce morbidity.

Radiative recombination at low temperatures in GaAsN is often associated with localized excitons. In this short note, we report results from high-resolution time-resolved photoluminescence spectroscopy that indicate that excitons, localized or otherwise, cannot be involved in the recombination process of this alloy system. The risetime of the photoluminescence signal is more than two orders of magnitude shorter than that expected, and found from excitonic recombination in other III–V materials, such as GaAs. We suggest that the radiative recombination in GaAsN takes place between localized electrons and delocalized holes.

The Department of Sexually Transmitted Infections (STI) Control (DSC) Clinic is the only public STI clinic in Singapore. This study aimed to determine patients' perception of the clinic as well as the factors that may influence their choice of DSC Clinic over other medical facilities. The concerns of certain risk groups were also assessed.Self-administered anonymous questionnaires were offered to Singaporeans and Permanent Residents over 18 years of age who were seeking treatment at the DSC Clinic. 1,000 responses were collected over a period of four weeks in May 2009.More than two-thirds of the patients had a positive experience at the DSC Clinic and would recommend the clinic to their family and friends. Positive attributes included competence of staff and the convenience of a one-stop treatment facility. The patients' visits to the DSC Clinic also prompted them to engage in safer sexual practices. Stigma was surprisingly not an issue among more than three-quarters of the patients. Confidentiality of medical records was a major concern, with more than half of the patients unwilling to share their records with other healthcare providers, employers or insurance companies. The majority of patients would like to see the provision of clinics catering to special groups such as young people, women as well as men-who-have-sex-with-men.The majority of patients were satisfied with the health services provided at the DSC Clinic. Confidentiality in consultation was of prime importance to patients.