Computational Screening of a Single-Atom Catalyst Supported by Monolayer Nb2S2C for Oxygen Reduction Reaction.

The search for high-performance catalysts to improve the catalytic activity for an oxygen reduction reaction (ORR) is crucial for developing a proton exchange membrane fuel cell. Using the first-principles method, we have performed computational screening on a series of transition metal (TM) atoms embedded in monolayer Nb2S2C to enhance the ORR activity. Through the scaling relationship and volcano plot, our results reveal that the introduction of a single Ni or Rh atom through substitutional doping into monolayer Nb2S2C yields promising ORR catalysts with low overpotentials of 0.52 and 0.42 V, respectively. These doped atoms remain intact on the monolayer Nb2S2C even at elevated temperatures. Importantly, the catalytic activity of the Nb2S2C doped with a TM atom can be effectively correlated with an intrinsic descriptor, which can be computed based on the number of d orbital electrons and the electronegativity of TM and O atoms.

Structural control of the dielectric, pyroelectric and ferroelectric properties of poly(vinylidene fluoride-co-trifluoroethylene) thin films.

The effects of solvents and temperature on the crystal formation were investigated for vinylidene fluoride/trifluoroethylene copolymer P(VDF-TrFE). Highly crystalline P(VDF-TrFE) thin films were fabricated by spin-casting using various polar solvents such as diethyl carbonate (DEC), methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Ferroelectric polarisation reversal of the P(VDF-TrFE) was evidenced by a displacement (D)-electric field (E) hysteresis loop measurement and supported by the presence of pyroelectric activity. The samples which were annealed above 100 °C gave elongated rod-like crystalline structures and the highest crystallinity, Xc of 83% was formed at 120 °C. Consequently, remnant polarisation (85 mC m-2) and the pyroelectric coefficient (30 µC m-2 K-1) were enhanced. Thus, annealing plays a substantial role in controlling the crystalline structure of P(VDF-TrFE) films regardless of the choice of solvent. Although, the crystalline structure control is almost independent of the solvent's polarity, the choice of solvent is essential in preparing a smoother film surface. Molecular dynamics of P(VDF-TrFE) are discussed from the observation of two dielectric relaxation processes, ß and γ related to the segmental micro-Brownian and local modes, respectively. The complete ferroelectric polarization reversal caused a reduction in the dielectric polarization and reduced the lattice spacing of the 110/200 planes.

The incidence of congenital syphilis in the United Kingdom: February 2010 to January 2015.

OBJECTIVE: To estimate the incidence of congenital syphilis in the UK. DESIGN: Prospective study. SETTING AND POPULATION: United Kingdom. METHODS: Children born between February 2010 and January 2015 with a suspected diagnosis of congenital syphilis were reported through an active surveillance system. MAIN OUTCOME MEASURES: Number of congenital syphilis cases and incidence. RESULTS: For all years, reported incidence was below the WHO threshold for elimination (<0.5/1000 live births). Seventeen cases (12 male, five female) were identified. About 50% of infants (8/17) were born preterm (<37 weeks' gestation): median birthweight 2000 g (865-3170 g). Clinical presentation varied from asymptomatic to acute disease, including severe anaemia, hepatosplenomegaly, rhinitis, thrombocytopaenia, skeletal damage, and neurosyphilis. One infant was deaf and blind. Median maternal age was 20 years (17-31) at delivery. Where maternal stage of infection was recorded, 6/10 had primary, 3/10 secondary and 1/10 early latent syphilis. Most mothers were white (13/16). Country of birth was recorded for 12 mothers: UK (n = 6), Eastern Europe (n = 3), Middle East (n = 1), and South East Asia (n = 2). The social circumstances of mothers varied and included drug use and sex work. Some experienced difficulty accessing health care. CONCLUSION: The incidence of congenital syphilis is controlled and monitored by healthcare services and related surveillance systems, and is now below the WHO elimination threshold. However, reducing the public health impact of this preventable disease in the UK is highly dependent on the successful implementation of WHO elimination standards across Europe. TWEETABLE ABSTRACT: Congenital syphilis incidence in the UK is at a very low level and well below the WHO elimination threshold.

Third-generation modular mandible endoprosthesis in Macaca fascicularis.

The aim of this study was to develop a third-generation modular mandible endoprosthesis that would experience less stress concentration at its stems compared to earlier generations, thereby minimizing micromotion and achieving long-term stability. In this three-piece modular design, different degrees of movement were incorporated between the endoprosthesis module interfaces. It was hypothesized that this unique feature would minimize stress concentration at the stems and hence promote osseointegration during the early phase of implantation. The endoprosthesis system was made of commercially pure grade 4 titanium, machined and surface-treated, then sterilized and implanted in segmental mandible defects of nine Macaca fascicularis. Clinical, radiological, histological, and histomorphometric evaluations were performed 4 months post-implantation. The endoprosthesis systems with a degree of movement incorporated, exhibited superior performance compared to the rigid system: 30.9-34.8 times higher percentage bone-implant contact (P< 0.0001) and 3.4-4.1 times higher percentage bone area (P<0.0001), with osseointegration noted at the posterior stems. However, fibrous tissue encapsulation was noted around the majority of the anterior stems in all groups. Although the degree of movement was favourable for improving bone healing and stability of the endoprosthesis system, more work needs to be done to investigate other strategies to further reduce loading on the endoprosthesis to achieve predictable osseointegration at the stems.

Acute syphilitic interstitial orchitis mimicking testicular malignancy in an HIV-1 infected man diagnosed by Treponema pallidum polymerase chain reaction.

We report a case of acute epididymo-orchitis due to early infectious syphilis, mimicking as testicular malignancy in an undiagnosed HIV-positive individual. He presented with a mass on his testicle and simultaneously had serology consistent with early syphilis. It could not be distinguished from a malignancy, which necessitated urgent orchidectomy. Histology showed endarteritis but no evidence of gummatous involvement. Although treponemes were not detected by staining, the diagnosis was confirmed by the first reported use of Treponema pallidum polymerase chain reaction in a testicular specimen in the UK.

Acute syphilitic posterior placoid chorioretinitis in late latent syphilis.

Diverse manifestations of ocular syphilis may involve any structure in the eye, at any stage of the disease. Posterior uveitis in the form of posterior placoid chorioretinitis has been described in secondary- and tertiary-acquired syphilis. In this case report, we present a 47-year-old man with late latent syphilitic infection and fundoscopic, as well as angiographic findings consistent with acute syphilitic posterior placoid chorioretinitis. To our knowledge this form of patchy multifocal choroiditis has never been described in the latent stage of the disease.

Modular endoprosthesis for mandibular body reconstruction: a clinical, micro-CT and histologic evaluation in eight Macaca fascicularis.

This paper presents the results of an animal experiment, in which a modular endoprosthesis is tested to replace a resected part of the mandible. The prostheses were fixed with polymethacrylate (PMMA) cement into the medullar space of the stumps. Clinical, radiologic, micro-computed tomographic and histologic evaluations were made after 3 and 6 months on four Macaca fascicularis for each implantation time. The prosthesis had not loosened but there were some loose screws that had caused fistulas in three animals. The stems of the modules were stably fixed with PMMA cement, surrounded by a fibrous capsule with inflammatory cells. This capsule was thinner in the 6-month group and showed less inflammatory infiltrate compared with the 3-month group; this was not statistically significant. There was an increase in woven bone surrounding the modules after 6 months. After 3 months of implantation, there was a considerable inflammatory reaction in the soft tissues surrounding the module, which subsided over following 3 months. The results are encouraging, but a longer period of follow-up is required to assess its application in a clinical setting, and some design drawbacks need to be addressed.

Modular endoprosthesis for mandibular reconstruction: a preliminary animal study.

The use of a mandibular modular endoprosthesis after segmental resection of part of the body of the mandible was studied. This preliminary study was carried out on four pigs and four monkeys. The devices were made of a titanium alloy and were cemented in the prepared medullary spaces with polymethylmetacrylate cement. The prosthesis failed in one pig, but in the other animals the prostheses were stable and firmly fixed to the stumps after 3 months. It was concluded that the endoprosthesis has potential in reconstructive surgery of the mandible, but that further studies are necessary to substantiate this claim. Pigs are not suitable for further studies as the medullary space is too large and filled with fat. They are also too big to handle and the variations in size and shape of the mandibles precludes the use of a modular system.

Patient-initiated digital photography in Peyronie's disease.

The introduction of digital camera and phone camera without having to develop images by a third party has simplified photography for everyday use. Digital imaging by patients can assist the assessment of medical conditions. We describe four male patients attending our department in whom digital imaging initiated by the patients was deemed to be helpful in supporting the diagnosis and assessing the severity of Peyronie's disease.

Can chlamydial conjunctivitis result from direct ejaculation into the eye?

The majority of cases of chlamydial conjunctivitis are thought to result from autoinoculation by the patient of infected genital secretions from themselves or their sexual partners. We noted that some patients had developed symptoms following direct ejaculation into the affected eye. We describe four cases of chlamydial conjunctivitis following ejaculation of semen directly into the eye, which have not been previously described. In only one case was chlamydia detected in the genital tract. In three cases, there was no evidence of genital chlamydial infection; the sources of the eye infection being either from infected genital material of their sexual partners transferred by hands to the eyes, or more likely from direct ejaculate inoculation. It is likely that this mode of transmission is underestimated as a history of ejaculation into the conjunctiva is not normally asked for.

The Department of Health recurrent-targeted funding for GU medicine clinics: what happened to the funding?

The Department of Health provided two recurrent targeted funding of 5 million pounds sterlings and 3 million pounds sterlings for genitourinary (GU) medicine services in 2003 in response to the increasing waiting times for appointments. The British Association for Sexual Health and HIV conducted a survey to find out if the clinics continued to receive their full allocation, if not, the reasons for it, and the workload change from 2002 to 2004. Out of a total of 91 responders, 78 were from acute trusts and 13 from primary care trusts (PCTs). Of the acute trusts and PCTs, respectively, 67.9% and 76.9% received the full allocation; overall 30.8% did not receive their full allocation. In all, 86% of clinics had increases in their workload and of the 26 clinics with shortfall of funds, 24 (92.3%) still managed to increase the workload. This survey showed that the funding and other measures have increased the workload capacity, and also highlights the continuing problem of many clinics in not receiving their full allocation. Such clinics should be targeted for early review by Medical Foundation for AIDS and Sexual Health with involvement of the Special Health Authorities and PCTs in the current national review of GU services.

Orbital implant placement using a computer-aided design and manufacturing (CAD/CAM) stereolithographic surgical template protocol.

Surgical implant placement in the orbital region for the support of a prosthesis is challenging due to the thin orbital rim and proximity to vital structures. This article reports the use of a computer-aided design and manufacturing (CAD/CAM) stereolithographic surgical template protocol for orbital implant placement in four patients, who were followed-up for about 7 years. A total of 11 orbital implants were inserted, eight of these in irradiated bone. No intraoperative complications were noted in any of the patients and the implants were all inserted in the planned positions. The survival rate of implants placed in irradiated bone that received hyperbaric oxygen therapy was 62.5% (5/8). One implant failed in a burns injury patient at 74 months after functional loading. The overall survival of implants in the orbital region and the cumulative survival at 7 years was 63.6%. With regard to skin reactions around the abutments, 85% were grade 0, 13% were grade 1, and 2% were grade 2 according to the Holgers classification. The mean survival time of the first prosthesis was 49 months. High patient satisfaction was achieved with the implant-retained orbital prostheses.

Adult gonococcal keratoconjunctivitis with AIDS.

Gonococcal eye infection in adults is an uncommon cause of blindness, where prompt diagnosis and effective treatment are essential in the prevention of ophthalmic morbidity. We present a case report detailing the management and complications encountered in this condition in a patient coinfected with human immunodeficiency virus (HIV).

Penicillinase-producing Neisseria gonorrhoeae: epidemiology, antimicrobial susceptibility and plasmid types.

Between 1976 and 1984 204 infections by penicillinase-producing Neisseria gonorrhoeae (PPNG) were seen in the Whitechapel Clinic. In 1984 PPNG were isolated from 4.7% of all patients attending with gonorrhoea. Three infections were homosexually acquired; 140 infections (68%) were acquired in the U.K. Strains that were tested were fully sensitive to spectinomycin (190), cefuroxime (177), kanamycin (170), amoxycillin combined with clavulanic acid (24) and rosoxacin (18). Of 135 strains 61% were resistant to co-trimoxazole, 69% of 169 to tetracycline (MIC greater than or equal to I mg/l) and 32% of 75 to streptomycin. Of 109 strains subjected to plasmid typing, 72(66%) were Asian strains. Of these, 55 (50% of the total) were without and 17 (16% of the total) possessed the 24.5 Mdal transfer plasmid; 27 (25%) were African strains without and 10 (9%) with the transfer plasmid. Of the Asian strains 10 were acquired in Africa. All four plasmid-containing strains are now endemic in the U.K. On the basis of the sensitivity tests, spectinomycin, cefuroxime and kanamycin should be effective in treatment, but not co-trimoxazole and tetracycline.

Chronic penile oedema secondary to chronic masturbation.

We report the case of a man with proven chlamydial conjunctivitis and urethritis who was found to have asymptomatic chronic penile oedema secondary to masturbation.

AIDS defining conditions in Africans resident in the United Kingdom.

A retrospective study of 55 HIV-1 seropositive African patients living in the UK, seen between January 1986 and November 1993, showed a total of 26 (47%) patients with AIDS. Thirty-one (56%) had symptomatic HIV disease at the time of presentation of whom 19 (34.5%) had an AIDS defining condition. Tuberculosis was the most common AIDS defining illness, accounting for 27% of all initial AIDS diagnoses, followed by by Pneumocystis carinii pneumonia and oesophageal candidiasis in 19% each and chronic mucocutaneous genital herpes in 15%. The mean CD4 count at the time of the first AIDS defining event was 91 x 10/mm3 (range 4-320 x 10/mm3). The profile of AIDS defining illnesses was different to published data of homosexual men and injecting drug users in the UK. This has practical implications when considering differential diagnoses and screening as well as prophylaxis for opportunistic infections in this group of patients.

Chlamydial ocular infection: efficacy of partner notification by patient referral.

Records on 254 patients with chlamydial ocular infection observed over a period of 67 months at the Moorfield's Eye Hospital were reviewed retrospectively in relation to sexual partners in the 6 months prior to diagnosis. Contactable partners were given an appointment through index patients to attend our clinic. Those unable to attend were issued contact slips, as used by the sexually transmitted disease (STD) clinics in the United Kingdom, to attend elsewhere: 175/328 (53%) of all partners were seen in our clinic: 161/218 (74%) of current regular partners compared to only 7/57 (12%) of ex-regular and 7/53 (13%) of casual partners. However, of those given appointments 175/201 (87%) attended: 161/179 (90%) of current regular, 7/14 (50%) of ex-regular and 7/8 (88%) of casual partners. Seventy of 328 (21%) of all partners were issued contact slips, of whom 47/70 (67%) were reported to have attended elsewhere. No contact slips were returned by other clinics, indicating a failure in the contact slip system. Thirty-five of 53 (66%) of casual, 22/57 (39%) of ex-regular and none of the current regular partners were untraceable. One hundred and five of 196 (54%) female partners were examined, of whom 59/105 (56%) had chlamydial genital infection, 45/105 (43%) had other genital infections and 35/105 (33%) had multiple genital infections. Seventy of 132 (53%) male partners were examined, of whom 58/70 (83%) had chlamydial or non-specific urethritis, 5/70 (7%) had other genital infections and 4/70 (6%) had multiple genital infections. Partner notification is important to interrupt chlamydia transmission.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for tuberculosis in an east London HIV clinic.

A prospective study was carried out to assess the value of routine skin tuberculin testing and chest radiography in HIV seropositive patients, attending the Genitourinary Medicine (GUM) clinic between July 1991-May 1992. 144 consecutive HIV seropositive patients had tuberculin Tine tests and chest radiographs performed. Ten patients were treated for active tuberculosis (TB) on the basis of abnormal radiography with or without strongly positive (Grade 3/4) skin tuberculin tests. A further 10 patients received prophylaxis on the basis of abnormal chest radiography consistent with previous tuberculous infection or strongly positive tuberculin tests. Active or previous tuberculous infection was found in the UK born Caucasian homosexual population as well as in injecting drug users and patients who were born in areas of high TB prevalence. Screening for TB in HIV seropositive patients is important both for detecting asymptomatic tuberculous infection and for recognizing patients at risk for reactivation of latent TB. We showed a high pick-up rate with 20 out of 144 patients having treatment as a result of screening.

The importance of routine magnetic resonance imaging in trigeminal neuralgia diagnosis.

The aim of the study was to determine the frequency of structural lesions diagnosed on magnetic resonance imaging (MRI) in a sample of patients with trigeminal neuralgia (TN) and to compare history and clinical features between the groups with and without structural lesions. Clinical records and MRI findings of 42 consecutive patients diagnosed with TN at the National Dental Centre, Singapore, and who underwent routine MRI examinations at diagnostic workup between April 1997 and March 1999 were retrospectively studied. Of these, 6 (14.3%; 95% confidence interval, 0 to 28.8%) were diagnosed with an associated structural lesion. Mean age of the group with structural lesions was 53.3 years (standard deviation, 10.9 years) at presentation, there was female predominance (M:F = 1:2), and all (100.0%) gave a typical pain history and had unilateral involvement of a single division of the trigeminal nerve. Two patients (33.3%) had other cranial nerve abnormalities. Three patients (50.0%) had complete, 2 patients (33.3%) had partial, and 1 patient (16.7%) had poor response to medical therapy. None of these variables was statistically different from the group without structural lesions (cranial nerve abnormalities were not compared). In conclusion, the frequency of structural lesions associated with TN in our sample was relatively high. It is not possible to reliably identify high risk patients for selective MRI indication on the basis of history and clinical features. It may be prudent to consider routine MRI for all patients with TN to exclude structural lesions.

Odontoameloblastoma: report of a case.

Odontoameloblastoma is a very rare odontogenic tumour that is similar to ameloblastoma in its locally aggressive behaviour. Its clinical presentation, however, often mimics the more innocuous odontoma, and hence the recognition of its aggressive nature is commonly only ascertained after its histopathologic diagnosis following enucleation. This paper presents a case of odontoameloblastoma. Some of the difficulties that may be encountered in the diagnosis and treatment planning of odontoameloblastomas are discussed.