Remarkably Weak Anisotropy in Thermal Conductivity of Two-Dimensional Hybrid Perovskite Butylammonium Lead Iodide Crystals.

Two-dimensional (2D) hybrid organic-inorganic perovskites consisting of alternating organic and inorganic layers are a new class of layered structures. They have attracted increasing interest for photovoltaic, optoelectronic, and thermoelectric applications, where knowing their thermal transport properties is critical. We carry out both experimental and computational studies on thermal transport properties of 2D butylammonium lead iodide crystals and find their thermal conductivity is ultralow (below 0.3 W m-1 K-1) with very weak anisotropy (around 1.5) among layered crystals. Further analysis reveals that the unique structure with the preferential alignment of organic chains and complicated energy landscape leads to moderately smaller phonon lifetimes in the out-of-plane direction and comparable phonon group velocities in in-plane and out-of-plane directions. These new findings may guide the future design of novel hybrid materials with desired thermal conductivity for various applications.

Generic health literacy measurement instruments for children and adolescents: a systematic review of the literature.

BACKGROUND: Health literacy is an important health promotion concern and recently children and adolescents have been the focus of increased academic attention. To assess the health literacy of this population, researchers have been focussing on developing instruments to measure their health literacy. Compared to the wider availability of instruments for adults, only a few tools are known for younger age groups. The objective of this study is to systematically review the field of generic child and adolescent health literacy measurement instruments that are currently available. METHOD: A systematic literature search was undertaken in five databases (PubMed, CINAHL, PsycNET, ERIC, and FIS) on articles published between January 1990 and July 2015, addressing children and adolescents ≤18 years old. Eligible articles were analysed, data was extracted, and synthesised according to review objectives. RESULTS: Fifteen generic health literacy measurement instruments for children and adolescents were identified. All, except two, are self-administered instruments. Seven are objective measures (performance-based tests), seven are subjective measures (self-reporting), and one uses a mixed-method measurement. Most instruments applied a broad and multidimensional understanding of health literacy. The instruments were developed in eight different countries, with most tools originating in the United States (n = 6). Among the instruments, 31 different components related to health literacy were identified. Accordingly, the studies exhibit a variety of implicit or explicit conceptual and operational definitions, and most instruments have been used in schools and other educational contexts. While the youngest age group studied was 7-year-old children within a parent-child study, there is only one instrument specifically designed for primary school children and none for early years. CONCLUSIONS: Despite the reported paucity of health literacy research involving children and adolescents, an unexpected number of health literacy measurement studies in children's populations was found. Most instruments tend to measure their own specific understanding of health literacy and not all provide sufficient conceptual information. To advance health literacy instruments, a much more standardised approach is necessary including improved reporting on the development and validation processes. Further research is required to improve health literacy instruments for children and adolescents and to provide knowledge to inform effective interventions.

Correction to: Traumatic inferior shoulder dislocation: a review of management and outcome.

The original version of this article unfortunately contained mistakes. The presentation of the author names was incorrect.

Traumatic inferior shoulder dislocation: a review of management and outcome.

INTRODUCTION: Traumatic inferior shoulder dislocation (ISD) is rare, estimated to occur in 0.5% of all shoulder dislocations. We describe the demographics, natural history and outcome of this injury. HYPOTHESIS/AIM: The aim of the study is to provide a summary of the demographics, clinical presentation, management and outcome of patients who suffer ISD METHODS: We conducted a systematic review of the English language literature on ISD using PubMed, Medline, CINHAL, Cochrane Database and Evidence-Based Medicine Reviews. Articles were examined independently by two of the authors and data were extracted using a standard form. Descriptive statistics were performed. RESULTS: 199 patients were identified, from 101 articles. Mean age was 44 years (range 13-94 years). All cases were caused by trauma, with falls accounting for 44% of all cases. There were three reported cases (2%) of open dislocations and 29 cases (15%) of bilateral ISD. Proximal humerus and scapular fractures were reported in 39 and 8% of patients, respectively. Neurological injury after dislocation was noted in 58 patients (29%). Vascular injury was noted in 20 patients (10%), which included axillary arterial injury in 19 patients and an upper limb deep vein thrombosis in one patient. Follow-up data were available for 107 patients (54%), with an average duration of 2.7 years (1 week-32 years). Avascular necrosis (AVN) was noted between 8 weeks and 2 years after initial injury in three patients (1.5%). CONCLUSION: Clinical and radiographic assessment of ISD is key to diagnosis and successful reduction. Patients can be treated with shoulder immobilisation for 2-3 weeks. In the setting of ongoing pain or instability, further imaging should be performed. The outcome of ISD is generally favourable.

Health literacy in childhood and youth: a systematic review of definitions and models.

BACKGROUND: Children and young people constitute a core target group for health literacy research and practice: during childhood and youth, fundamental cognitive, physical and emotional development processes take place and health-related behaviours and skills develop. However, there is limited knowledge and academic consensus regarding the abilities and knowledge a child or young person should possess for making sound health decisions. The research presented in this review addresses this gap by providing an overview and synthesis of current understandings of health literacy in childhood and youth. Furthermore, the authors aim to understand to what extent available models capture the unique needs and characteristics of children and young people. METHOD: Six databases were systematically searched with relevant search terms in English and German. Of the n = 1492 publications identified, N = 1021 entered the abstract screening and N = 340 full-texts were screened for eligibility. A total of 30 articles, which defined or conceptualized generic health literacy for a target population of 18 years or younger, were selected for a four-step inductive content analysis. RESULTS: The systematic review of the literature identified 12 definitions and 21 models that have been specifically developed for children and young people. In the literature, health literacy in children and young people is described as comprising variable sets of key dimensions, each appearing as a cluster of related abilities, skills, commitments, and knowledge that enable a person to approach health information competently and effectively and to derive at health-promoting decisions and actions. DISCUSSION: Identified definitions and models are very heterogeneous, depicting health literacy as multidimensional, complex construct. Moreover, health literacy is conceptualized as an action competence, with a strong focus on personal attributes, while also recognising its interrelatedness with social and contextual determinants. Life phase specificities are mainly considered from a cognitive and developmental perspective, leaving children's and young people's specific needs, vulnerabilities, and social structures poorly incorporated within most models. While a critical number of definitions and models were identified for youth or secondary school students, similar findings are lacking for children under the age of ten or within a primary school context.

Validation of a questionnaire to measure sexual health knowledge and understanding (Sexual Health Questionnaire) in Nepalese secondary school: A psychometric process.

BACKGROUND: School-based sex education has the potential to prevent unwanted pregnancy and to promote positive sexual health at the individual, family and community level. OBJECTIVES: To develop and validate a sexual health questionnaire to measure young peoples' sexual health knowledge and understanding (SHQ) in Nepalese secondary school. MATERIALS AND METHODS: Secondary school students (n = 259, male = 43.63%, female = 56.37%) and local experts (n = 9, male = 90%, female = 10%) were participated in this study. Evaluation processes were; content validity (>0.89), plausibility check (>95), item-total correlation (>0.3), factor loading (>0.4), principal component analysis (4 factors Kaiser's criterion), Chronbach's alpha (>0.65), face validity and internal consistency using test-retest reliability (P > 0.05). RESULTS: The principal component analysis revealed four factors to be extracted; sexual health norms and beliefs, source of sexual health information, sexual health knowledge and understanding, and level of sexual awareness. Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy demonstrated that the patterns of correlations are relatively compact (>0.80). Chronbach's alpha for each factors were above the cut-off point (0.65). Face validity indicated that the questions were clear to the majority of the respondent. Moreover, there were no significant differences (P > 0.05) in the responses to the items at two time points at seven weeks later. CONCLUSIONS: The finding suggests that SHQ is a valid and reliable instrument to be used in schools to measure sexual health knowledge and understanding. Further analysis such as structured equation modelling (SEM) and confirmatory factor analysis could make the questionnaire more robust and applicable to the wider school population.

Luxatio erecta humeri with neurovascular compromise: inferior glenohumeral dislocation illustrating associated injuries.

Luxatio erecta humeri (LEH) is a rare type of shoulder dislocation in which the humeral head becomes trapped beneath the glenoid. Patients present with the arm in a fixed hyperabducted position. LEH is estimated to occur in 0.5% of all shoulder dislocations, most often caused by trauma and has a significant association with local bone, ligament and less frequently neurovascular injury. We present a case with initial neurovascular compromise and sustained neurological impairment at long-term follow-up. Urgent closed reduction is advocated and subsequent treatment is dependent on associated injuries.

Live attenuated tetravalent dengue virus host range vaccine is immunogenic in African green monkeys following a single vaccination.

UNLABELLED: The causative agent of dengue fever, dengue virus (DENV), is transmitted by mosquitoes, and as distribution of these insects has expanded, so has dengue-related disease. DENV is a member of the Flaviviridae family and has 4 distinct serotypes (DENV-1, -2, -3, and -4). No lasting cross protection is afforded to heterologous serotypes following infection by any one of the individual serotypes. The presence of nonneutralizing antibodies to one serotype can facilitate the occurrence of more-severe dengue hemorrhagic fever through immune enhancement upon infection with a second serotype. For this reason, the development of a safe, tetravalent vaccine to produce a balanced immune response to all four serotypes is critical. We have developed a novel approach to produce safe and effective live-attenuated vaccines for DENV and other insect-borne viruses. Host range (HR) mutants of each DENV serotype were created by truncating transmembrane domain 1 of the E protein and selecting for strains of DENV that replicated well in insect cells but not mammalian cells. These vaccine strains were tested for immunogenicity in African green monkeys (AGMs). No vaccine-related adverse events occurred. The vaccine strains were confirmed to be attenuated in vivo by infectious center assay (ICA). Analysis by 50% plaque reduction neutralization test (PRNT50) established that by day 62 postvaccination, 100% of animals seroconverted to DENV-1, -2, -3, and -4. Additionally, the DENV HR tetravalent vaccine (HR-Tet) showed a tetravalent anamnestic immune response in 100% (16/16) of AGMs after challenge with wild-type (WT) DENV strains. IMPORTANCE: We have generated a live attenuated viral (LAV) vaccine capable of eliciting a strong immune response in African green monkeys (AGMs) in a single dose. This vaccine is delivered by injecting one of four attenuated serotypes into each limb of the animal. 100% of animals given the vaccine generated antibodies against all 4 serotypes, and this response was found to be balanced in nature. This is also one of the first studies of dengue in AGMs, and our study suggests that viremia and antibody response in AGMs may be similar to those seen in DENV infection in humans.

The natural history of ceramic-on-ceramic prosthetic hip squeak and its impact on patients.

BACKGROUND: Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) has been scrutinised for a high incidence of post-operative squeak. The psychological and social consequences, and subsequent request for revision surgery are not well documented. METHODS: Seventy consecutive primary CoC THA operated on by a single surgeon at a single institution were enroled and followed for an average 7.1 years. Information was obtained from routine post-operative review, medical records, mailed questionnaire and periodic phone interview. RESULTS: Of 70 THA, 69 were available for follow-up. Seventeen (24.6 %) reported at least one instance of squeak, occurring on average 34.2 months post-operatively. Five (7.5 %) recalled being warned preoperatively of squeak as a potential complication. Six reported infrequent squeak and 11 frequent squeak. Ten were concerned, reporting embarrassment, harassment and anxiety regarding the longevity of their THA. One patient was planning revision surgery. DISCUSSION: This study demonstrates the highest published prevalence of squeaking CoC THA and highlights the importance of warning patients of this potential complication.

Chikungunya virus host range E2 transmembrane deletion mutants induce protective immunity against challenge in C57BL/6J mice.

A vaccine against Chikungunya virus (ChikV), a reemerging pathogenic arbovirus, has been made by attenuating wild-type (WT) virus via truncation of the transmembrane domain (TMD) of E2 and selecting for host range (HR) mutants. Mice are a standard model system for ChikV disease and display the same symptoms of the disease seen in humans. Groups of mice were inoculated with one of three ChikV HR mutants to determine the ability of each mutant strain to elicit neutralizing antibody and protective immunity upon virus challenge. One mutant, ChikV TM17-2, fulfilled the criteria for a good vaccine candidate. It displayed no reactogenicity at the site of injection, no tissue disease in the foot/ankle and quadriceps, and no evidence of viral persistence in foot/ankle tissues 21 days after infection. Upon challenge with a highly pathogenic strain of ChikV, the mutant blocked viral replication in all tissues tested. This study identified a ChikV HR mutant that grows to high levels in insect cells but was restricted in the ability to assemble virus in mammalian cells in vitro. The study demonstrates that these HR strains are attenuated in the mammalian host and warrant further development as live-attenuated vaccine strains.

Testing of novel dengue virus 2 vaccines in African green monkeys: safety, immunogenicity, and efficacy.

The immunogenicity and safety of three novel host-range vaccines containing deletions in the transmembrane domain of dengue virus serotype 2 (DV2) E glycoprotein were evaluated in African green monkeys. The shorter transmembrane domains are capable of functionally spanning an insect but not a mammalian cell membrane, resulting in production of viral mutants that have reduced infectivity in mammalian hosts but efficient growth in insect cells. Groups of four monkeys received one dose each of test vaccine candidate with no booster immunization. After immunization, levels of viremia produced by each vaccine were determined by infectious center assay. Vaccine recipient immune response to wild-type DV2 challenge was measured on Day 57 by enzyme-linked immunosorbent assay and plaque reduction neutralization test. Two vaccines, DV2ΔGVII and DV2G460P, generated neutralizing antibody in the range of 700-900 50% plaque reduction neutralization test units. All three vaccine strains decreased the length of viremia by at least two days. No safety concerns were identified.

Imaging "invisible" dopant atoms in semiconductor nanocrystals.

Nanometer-scale semiconductors that contain a few intentionally added impurity atoms can provide new opportunities for controlling electronic properties. However, since the physics of these materials depends strongly on the exact arrangement of the impurities, or dopants, inside the structure, and many impurities of interest cannot be observed with currently available imaging techniques, new methods are needed to determine their location. We combine electron energy loss spectroscopy with annular dark-field scanning transmission electron microscopy (ADF-STEM) to image individual Mn impurities inside ZnSe nanocrystals. While Mn is invisible to conventional ADF-STEM in this host, our experiments and detailed simulations show consistent detection of Mn. Thus, a general path is demonstrated for atomic-scale imaging and identification of individual dopants in a variety of semiconductor nanostructures.

Structural mutants of dengue virus 2 transmembrane domains exhibit host-range phenotype.

BACKGROUND: There are over 700 known arboviruses and at least 80 immunologically distinct types that cause disease in humans. Arboviruses are transmitted among vertebrates by biting insects, chiefly mosquitoes and ticks. These viruses are widely distributed throughout the world, depending on the presence of appropriate hosts (birds, horses, domestic animals, humans) and vectors. Mosquito-borne arboviruses present some of the most important examples of emerging and resurgent diseases of global significance. METHODS: A strategy has been developed by which host-range mutants of Dengue virus can be constructed by generating deletions in the transmembrane domain (TMD) of the E glycoprotein. The host-range mutants produced and selected favored growth in the insect hosts. Mouse trials were conducted to determine if these mutants could initiate an immune response in an in vivo system. RESULTS: The DV2 E protein TMD defined as amino acids 452SWTMKILIGVIITWIG467 was found to contain specific residues which were required for the production of this host-range phenotype. Deletion mutants were found to be stable in vitro for 4 sequential passages in both host cell lines. The host-range mutants elicited neutralizing antibody above that seen for wild-type virus in mice and warrant further testing in primates as potential vaccine candidates. CONCLUSIONS: Novel host-range mutants of DV2 were created that have preferential growth in insect cells and impaired infectivity in mammalian cells. This method for creating live, attenuated viral mutants that generate safe and effective immunity may be applied to many other insect-borne viral diseases for which no current effective therapies exist.

Health promotion and education policy and practice in urban schools in Liaoning province, China.

This paper reviews the status of health education in urban schools in three cities in Liaoning province, China. The cities represent the upper, middle and lower levels of city economy based on the GDP per person within the province. A self-administered questionnaire was provided to 500 primary and secondary schools and 436 questionnaires (87.2%) were returned completed. The questionnaire assessed health education offerings in the schools, permitting the comparison of similarities and differences in school practices, and the identification of obstacles that prevent schools becoming health promoting. The analysis revealed that 0.7% of schools fulfilled criteria for good status of health education. The negative attitudes of school management, teachers and pupils towards health education, as well as the lack of in-service training for staff, were perceived as key obstacles to school health education. Few provincial and school-based policies mentioned pupil involvement in health policy development and only a small number of schools acknowledged the need to improve community and parental involvement. In this paper we discuss the challenges facing provincial education and health authorities, and make recommendations about how to assist Chinese schools to develop and implement high quality health education initiatives.

Room design for high-performance electron microscopy.

Aberration correctors correct aberrations, not instabilities. Rather, as spatial resolution improves, a microscope's sensitivity to room environment becomes more noticeable, not less. Room design is now an essential part of the microscope installation process. Previously ignorable annoyances like computer fans, desk lamps and that chiller in the service corridor now may become the limiting factors in the microscopes performance. We discuss methods to quantitatively characterize the instrument's response to magnetic, mechanical, acoustical and thermal disturbances and thus predict the limits that the environment places on imaging and spectroscopy.