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Abstract Background Distal radius fractures are common. The increasing prevalence of osteoporosis contributes to frequently complex articular injuries sustained even after low energy falls. The best method of treating complex type C distal radius fractures is debated. Locked volar plating and external fixation are both widely used with good reported results. Measures of success are traditionally based on technical measurements or the perception of the surgeon. Patient reported measures of outcome are increasingly recognised as important markers of surgical success. We report our experience using locked volar plating for complex type C distal radius fractures as well as patient reported measures of success and satisfaction. Methods Over a 12 month period we treated 21 patients with type C distal radius fractures using locked volar plating. These patients were followed up for at least 12 months and the outcome was assessed using clinical examination, grip strength measurements, radiographs and Patient Rated Wrist Evaluation (PRWE) scoring. Results The 21 patients studied had an average age of 48 years. There were 8 men and 13 women. All of the fractures had united by 3 months. There were no cases of wound infection or tendon injury/irritation. Patients reported low pain scores, good patient rated wrist evaluation scores and high levels of satisfaction. Conclusions Locked volar plating for complex distal radius fractures produces good results when assessed using patient reported measures of outcome. Further work should address whether locked volar plating offers superior outcomes and patient satisfaction compared to external fixation.

Abstract Background Young maternal age has long been associated with higher infant mortality rates, but the role of socioeconomic factors in this association has been controversial. We sought to investigate the relationships between infant mortality (distinguishing neonatal from post-neonatal deaths), socioeconomic status and maternal age in a large, retrospective cohort study. Methods We conducted a population-based cohort study using linked birth-death certificate data for Missouri residents during 1997–1999. Infant mortality rates for all singleton births to adolescent women (12–17 years, n = 10,131; 18–19 years, n = 18,954) were compared to those for older women (20–35 years, n = 28,899). Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for all potential associations. Results The risk of infant (OR 1.95, CI 1.54–2.48), neonatal (1.69, 1.24–2.31) and post-neonatal mortality (2.47, 1.70–3.59) were significantly higher for younger adolescent (12–17 years) than older (20–34 years) mothers. After adjusting for race, marital status, age-appropriate education level, parity, smoking status, prenatal care utilization, and poverty status (indicated by participation in WIC, food stamps or Medicaid), the risk of post-neonatal mortality (1.73, 1.14–2.64) but not neonatal mortality (1.43, 0.98–2.08) remained significant for younger adolescent mothers. There were no differences in neonatal or post-neonatal mortality risks for older adolescent (18–19 years) mothers. Conclusion Socioeconomic factors may largely explain the increased neonatal mortality risk among younger adolescent mothers but not the increase in post-neonatal mortality risk.

This two-wave longitudinal study examined peer selection and influence pertaining to tobacco and alcohol use by adolescents and their friends in a sample of 854 Chinese adolescents (384 girls: mean age = 13.33 years). Participants nominated friends and self-reported their tobacco and alcohol use at seventh and again at eighth grade. Longitudinal social network analyses revealed evidence of friend influence but not selection over smoking and drinking. Boys increased their levels of smoking at rates greater than that of girls, but no sex moderation of either selection or influence was found. In interpreting these results, it is important to understand the gender norms for Chinese boys and girls and the cultural context of tobacco and alcohol use., (© 2023 Society for Research on Adolescence.)

Gender discrimination is a common experience for adolescent girls and has implications for their mental health and identity development. Guided by Phenomenological Variant of Ecological Systems Theory (PVEST; Spencer et al. 1997), this study examined the longitudinal and bidirectional associations between adolescent girls' experiences of gender discrimination, their internalizing symptoms, and gender identity. The sample was 161 adolescent girls (ages 14-17; M age  = 15.90) from across the United States (51% White; 17% African American, 11% Hispanic/Latina) who participated in a short-term longitudinal study of adolescent development. The results showed a reciprocal, longitudinal association between discrimination and internalizing symptoms. Discrimination also predicted longitudinal declines in gender identity, which was explained indirectly through internalizing symptoms. The findings implicate gender discrimination as a distinct risk factor during girls' developmental years, and underscore the importance of helping girls learn adaptive responses to sexism, while also reducing actual occurrence and exposure., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Gender similarity is an indicator of perceived fit with own-gender peers and other-gender peers and is strongly correlated with indicators of adolescent adjustment, including negative peer interactions. Although gender similarity is generally studied as a composite variable, evidence is increasing that peer victimization might be uniquely related to specific domains of gender similarity such as appearance or interests. A better understanding of the specific factors that motivate peer victimization will likely aid in intervention efforts. We analyzed five domains of own- and other-gender similarity (feelings, actions, appearance, preferences, time spent with peers) for adolescents, and explored whether they uniquely predicted negative peer interactions including general peer victimization (e.g., pushing/hitting) and experiencing or perpetrating gender-based peer victimization (e.g., anti-gay name-calling) over time. With 407 adolescents (14-17 years old, M age  = 15.42, 50% girls, 52% White) from two timepoints that were six months apart, we first conducted MANOVAs at T1 to assess gender differences in peer victimization experiences. Next, we conducted logistic regression path analyses to model the relation between gender similarity and peer victimization over time. Adolescents reported unique outcomes for different domains of gender similarity with girls focused on appearance and boys focused on not spending time with girls. We discuss how girls' and boys' experiences of gender similarity may be differentially informed by androcentric culture and how different expressions of gender uniquely provoke negative peer attention., Competing Interests: Conflict of InterestThere are no commercial, financial, or other associations that could pose a conflict of interest in connection with this article. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The authors declare no conflicts of interest., (© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022.)

Purpose: Recent studies have documented worrisome levels of hesitancy and resistance to the COVID-19 vaccine, including within the adolescent population. In this study, we examined attitudinal (perceived severity of COVID-19, vaccine-related concerns) and interpersonal (parent and peer norms) antecedents of adolescents' intentions to receive the COVID-19 vaccine., Methods: Participants were 916 adolescents (aged 12-17 years) from across the United States (47.3% male) representing diverse ethnic and socioeconomic backgrounds (26% African-American, 22% Hispanic/Latinx, 35% white, 7% Asian American). They completed a survey on their experiences and attitudes surrounding COVID-19 and the COVID-19 vaccine., Results: Parent and peer norms were distinct predictors of adolescent willingness to receive the vaccine. These norms were associated with vaccine intentions directly and indirectly through adolescents' beliefs about the vaccine's safety, efficacy, and necessity. Parent norms in particular displayed large effect sizes and explained considerable variance in adolescents' vaccine intentions., Conclusions: Parents and friends-who figure as adolescents' most salient interpersonal relationships-are key leveraging points in promoting adolescents' uptake of the COVID-19 vaccine. Norm interventions and family-based interventions may be successful in this regard., (Copyright © 2021 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Abstract: Most children with coronavirus disease 2019 (COVID-19) infection are asymptomatic or have mild disease. About 5% of infected children will develop severe or critical disease. Rapid identification and treatment are essential for children who are critically ill with signs and symptoms of respiratory failure, septic shock, and multisystem inflammatory syndrome in children. This article is intended for pediatricians, pediatric emergency physicians, and individuals involved in the emergency care of children. It reviews the current epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children, summarizes key aspects of clinical assessment including identification of high-risk patients and manifestations of severe disease, and provides an overview of COVID-19 management in the emergency department based on clinical severity., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

As powerful computational tools and 'big data' transform the biological sciences, bioinformatics training is becoming necessary to prepare the next generation of life scientists. Furthermore, because the tools and resources employed in bioinformatics are constantly evolving, bioinformatics learning materials must be continuously improved. In addition, these learning materials need to move beyond today's typical step-by-step guides to promote deeper conceptual understanding by students. One of the goals of the Network for Integrating Bioinformatics into Life Sciences Education (NIBSLE) is to create, curate, disseminate, and assess appropriate open-access bioinformatics learning resources. Here we describe the evolution, integration, and assessment of a learning resource that explores essential concepts of biological sequence similarity. Pre/post student assessment data from diverse life science courses show significant learning gains. These results indicate that the learning resource is a beneficial educational product for the integration of bioinformatics across curricula., Competing Interests: The authors have declared that no competing interests exist.

We examined the development of children's positive and negative attitudes toward other-gender peers over 1 year, and explored the longitudinal social consequences of holding positive or negative attitudes on the beholder of these attitudes. Participants were 206 second graders (Mage = 7.18 yrs, SD = .56, 50% girls) and 206 fourth graders (Mage = 9.10 yrs, SD = .66, 44.2% girls) from diverse ethnic racial backgrounds (54.6% White; 17.2% Latinx, 4.4% Black, 5.3% Asian, 2.9% Native American, .7% Pacific Islander, 13.1% other) with average household income ranged from $51,000 to $75,000, and they were assessed in 2 consecutive years. Developmental change was assessed using latent change score analysis, which showed that positive other-gender attitudes increased over time (for boys) whereas negative other-gender attitudes decreased for everyone. Path analyses showed that both positive and negative other-gender attitudes predicted children's perceptions of stressful other-gender interactions and their inclusion expectancies by other-gender peers longitudinally, controlling for same-gender attitudes. We also examined the extent to which the predicted relation between attitudes and inclusion expectancies was mediated by children's perceptions of stressful experiences with other-gender peers. We found that the extent of mediation varied by the type of attitudes and by children's age. Overall, findings contributed to the understanding of the development of children's other-gender attitudes, and underscored the consequences of these attitudes for the beholder of attitudes. This work also sheds light on the discussion of intervention strategies aimed at improving children's gender-based intergroup relations. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Most empirical research examining youth's gender development measures felt pressure to conform to gender norms using a composite value of felt pressure from multiple sources; however, because of the different socialization processes at work from parents, peers, and the self, analyzing these sources separately may elucidate different effects on gender development. Thus, the purpose of this study was to (a) differentiate the effects of perceived gender socialization pressure from parents, peers, and the self on early adolescents' own- and other-gender typicality, and (b) to examine whether a bi-directional relation between gender typicality and felt pressure is evident when distinguished across sources. With a sample of 212 early adolescents (54% girls; M age  = 11.11 years), felt pressure was found to be distinguishable by socialization source: adolescents' perceptions of parents, peers, and their own pressures were distinct, and each contributed differently to gender development. Pressure from self and peers were both found to relate concurrently to typicality (i.e., positively to own-gender typicality, negatively to other-gender typicality); only pressure from the self was found to have a longitudinal effect on adolescents' developing gender identity (i.e., an increase in own-gender typicality). Interestingly, other-gender typicality did not elicit higher felt pressure; in fact, it was negatively related to later felt pressure from the self, suggesting that adolescents may be developing self-acceptance of their levels of gender typicality. The findings suggest that the development of gender identity may involve a complex interplay with various sources of socialization pressures (e.g., parent, peers, self), and may further shift in relation to the adolescent's own levels of gender typicality.

Adolescents actively evaluate their identities during adolescence, and one of the most salient and central identities for youth concerns their gender identity. Experiences with peers may inform gender identity. Unfortunately, many youth experience homophobic name calling, a form of peer victimization, and it is unknown whether youth internalize these peer messages and how these messages might influence gender identity. The goal of the present study was to assess the role of homophobic name calling on changes over the course of an academic year in adolescents' gender identity. Specifically, this study extends the literature using a new conceptualization and measure of gender identity that involves assessing how similar adolescents feel to both their own- and other-gender peers and, by employing longitudinal social network analyses, provides a rigorous analytic assessment of the impact of homophobic name calling on changes in these two dimensions of gender identity. Symbolic interaction perspectives-the "looking glass self"-suggest that peer feedback is incorporated into the self-concept. The current study tests this hypothesis by determining if adolescents respond to homophobic name calling by revising their self-view, specifically, how the self is viewed in relation to both gender groups. Participants were 299 6th grade students (53% female). Participants reported peer relationships, experiences of homophobic name calling, and gender identity (i.e., similarity to own- and other-gender peers). Longitudinal social network analyses revealed that homophobic name calling early in the school year predicted changes in gender identity over time. The results support the "looking glass self" hypothesis: experiencing homophobic name calling predicted identifying significantly less with own-gender peers and marginally more with other-gender peers over the course of an academic year. The effects held after controlling for participant characteristics (e.g., gender), social network features (e.g., norms), and peer experiences (e.g., friend influence, general victimization). Homophobic name calling emerged as a form of peer influence that changed early adolescent gender identity, such that adolescents in this study appear to have internalized the messages they received from peers and incorporated these messages into their personal views of their own gender identity.

The use of multiple chromophores as photosensitizers for catalysts involved in energy-demanding redox reactions is often complicated by electronic interactions between the chromophores. These interchromophore interactions can lead to processes, such as excimer formation and symmetry-breaking charge separation (SB-CS), that compete with efficient electron transfer to or from the catalyst. Here, two dimers of perylene bound either directly or through a xylyl spacer to a xanthene backbone were synthesized to probe the effects of interchromophore electronic coupling on excimer formation and SB-CS using ultrafast transient absorption spectroscopy. Two time constants for excimer formation in the 1-25 ps range were observed in each dimer due to the presence of rotational isomers having different degrees of interchromophore coupling. In highly polar acetonitrile, SB-CS competes with excimer formation in the more weakly coupled isomers followed by charge recombination with τ CR = 72-85 ps to yield the excimer. The results of this study of perylene molecular dimers can inform the design of chromophore-catalyst systems for solar fuel production that utilize multiple perylene chromophores.

Two new covalently linked chromophore-CO 2 reduction catalyst systems were prepared using a perylene chromophore and a bis[(dicyclohexylphosphino)ethyl]phenylphosphinopalladium(II) catalyst. The primary goal of this study is to probe the influence of photosensitizer attachment on the electrocatalytic performance. The position either para or meta to the phosphorus on the phenyl group of the palladium complex was linked via a 2,5-xylyl group to the 3 position of perylene. The electrocatalytic CO 2 reduction activity of the palladium complex is maintained in the meta-linked system, but is lost in the para-linked system, possibly because of unfavorable interactions of the perylene chromophore with the glassy carbon electrode used. Following selective photoexcitation of the perylene, an enhanced perylene excited-state decay rate was observed in the palladium complexes compared to perylene attached to the free ligands. This decrease is accompanied by formation of the perylene cation radical, showing that electron transfer from perylene to the palladium catalyst occurs. Electron transfer and charge recombination were both found to be faster in the para-linked system than in the meta-linked one, which is attributed to stronger electronic coupling in the former. These results illustrate the need to carefully tune the electronic coupling between a photosensitizer chromophore and the catalyst to promote photodriven electron transfer yet inhibit adverse electronic effects of the chromophore on electrocatalysis.

This study examined children's expectancies about interactions with own- and other-gender peers. Goals were to examine expectancies about the outcomes related to own- versus other-gender group interactions, assess cohort and temporal changes in expectancies, and assess the effect of expectancies on school-related outcomes. Students in second and fourth grades (N = 412, 47% girls, Mage  = 7.15 and 9.10 years, respectively) were followed longitudinally for 1 year. Results supported hypotheses that social costs and inclusion-enjoyment that children expect in interactions with own- and other-gender peers represent four constructs. Expectancies varied by gender, age, and differentially predicted school outcomes with inclusion expectancies more strongly relating to outcomes than cost expectancies. Implications of children's expectancies about gendered contexts are discussed., (© 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.)

We report the photoluminescence (PL) properties of colloidal Si nanocrystals (NCs) up to 800 K and observe PL retention on par with core/shell structures of other compositions. These alkane-terminated Si NCs even emit at temperatures well above previously reported melting points for oxide-embedded particles. Using selected area electron diffraction (SAED), powder X-ray diffraction (XRD), liquid drop theory, and molecular dynamics (MD) simulations, we show that melting does not play a role at the temperatures explored experimentally in PL, and we observe a phase change to β-SiC in the presence of an electron beam. Loss of diffraction peaks (melting) with recovery of diamond-phase silicon upon cooling is observed under inert atmosphere by XRD. We further show that surface passivation by covalently bound ligands endures the experimental temperatures. These findings point to covalently bound organic ligands as a route to the development of NCs for use in high temperature applications, including concentrated solar cells and electrical lighting.

Uranium (U) poses a significant contamination hazard to soils, sediments, and groundwater due to its extensive use for energy production. Despite advances in modeling the risks of this toxic and radioactive element, lack of information about the mechanisms controlling U transport hinders further improvements, particularly in reducing environments where U(IV) predominates. Here we establish that mineral surfaces can stabilize the majority of U as adsorbed U(IV) species following reduction of U(VI). Using X-ray absorption spectroscopy and electron imaging analysis, we find that at low surface loading, U(IV) forms inner-sphere complexes with two metal oxides, TiO2 (rutile) and Fe3O4 (magnetite) (at <1.3 U nm(-2) and <0.037 U nm(-2), respectively). The uraninite (UO2) form of U(IV) predominates only at higher surface loading. U(IV)-TiO2 complexes remain stable for at least 12 months, and U(IV)-Fe3O4 complexes remain stable for at least 4 months, under anoxic conditions. Adsorbed U(IV) results from U(VI) reduction by Fe(II) or by the reduced electron shuttle AH2QDS, suggesting that both abiotic and biotic reduction pathways can produce stable U(IV)-mineral complexes in the subsurface. The observed control of high-affinity mineral surface sites on U(IV) speciation helps explain the presence of nonuraninite U(IV) in sediments and has important implications for U transport modeling.

Two new nanovehicles that have extended aromatic platforms as the cargo zones have been obtained. Two strategies were considered for the formation of the perylene core from two naphthalene precursors. The first was based on a Scholl-type reaction involving an oxidant, and the second used a brominated derivative to perform a homocoupling reaction. The first strategy failed under diverse coupling conditions in the presence of several strong oxidants. Nevertheless, the use of CoF(3) in trifluoroacetic acid triggered a dimerization reaction between two ester groups of one molecule and the naphthalene unit of another, thereby surprisingly yielding a ten-membered carbon macrocycle. The second strategy encountered a lack of reactivity of the substrate under several homocoupling conditions. The dimerization was not easily performed but Ullmann-type conditions ultimately gave the expected product. The low yield and low solubility of the product encouraged us to modify our initial design. The synthesis of a new chassis that incorporated additional tert-butyl groups improved the solubility of the molecules and also prevented overcyclization of the aromatic platform by blocking these positions. Some p-phenylene spacers were also intercalated between the iodine and perylene centers to increase the reactivity of the halide towards coupling reactions. Two new chassis were obtained by Scholl-type oxidative coupling using FeCl(3) as the oxidant. The introduction of four triptycene wheels allowed the formation of the two corresponding nanovehicles., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: A key challenge inhibiting the timely initiation of pediatric antiretroviral treatment is the loss to follow-up of mothers and their infants between the time of mothers' HIV diagnoses in pregnancy and return after delivery for early infant diagnosis of HIV. We sought to identify barriers to follow-up of HIV-exposed infants in rural Zambézia Province, Mozambique., Methods: We determined follow-up rates for early infant diagnosis and age at first test in a retrospective cohort of 443 HIV-infected mothers and their infants. Multivariable logistic regression models were used to identify factors associated with successful follow-up., Results: Of the 443 mother-infant pairs, 217 (49%) mothers enrolled in the adult HIV care clinic, and only 110 (25%) infants were brought for early infant diagnosis. The predictors of follow-up for early infant diagnosis were larger household size (odds ratio [OR], 1.29; 95% confidence interval [CI], 1.09-1.53), independent maternal source of income (OR, 10.8; 95% CI, 3.42-34.0), greater distance from the hospital (OR, 2.14; 95% CI, 1.01-4.51), and maternal receipt of antiretroviral therapy (OR, 3.15; 95% CI, 1.02-9.73). The median age at first test among 105 infants was 5 months (interquartile range, 2-7); 16% of the tested infants were infected., Conclusions: Three of four HIV-infected women in rural Mozambique did not bring their children for early infant HIV diagnosis. Maternal receipt of antiretroviral therapy has favorable implications for maternal health that will increase the likelihood of early infant diagnosis. We are working with local health authorities to improve the linkage of HIV-infected women to HIV care to maximize early infant diagnosis and care.

Although B cells are crucial antigen-presenting cells in the initiation of T cell autoimmunity to islet beta cell autoantigens in type 1 diabetes (T1D), adhesion molecules that control migration of B cells into pancreatic lymph nodes (PanLN) in the nonobese diabetic (NOD) mouse model of human T1D have not been defined. In this study, we found that B cells from PanLN of 3-4-week-old female NOD mice expressed high levels of alpha(4) integrin and LFA-1 and intermediate levels of beta(7) integrin; half of B cells were L-selectin(high). In short-term in vivo lymphocyte migration assays, B cells migrated from the bloodstream into PanLN more efficiently than into peripheral LNs. Moreover, antibodies to mucosal addressin cell adhesion molecule 1 (MAdCAM-1) and alpha(4)beta(7) integrin inhibited >90% of B cell migration into PanLN. In contrast, antibodies to peripheral node addressin, L-selectin or LFA-1 partially inhibited B cell migration into PanLN. Furthermore, one intraperitoneal injection of anti-MAdCAM-1 antibody into 3-week-old NOD mice significantly inhibited entry of B cells into PanLN for at least 2 weeks. Taken together, these results indicate that the alpha(4)beta(7) integrin/MAdCAM-1 adhesion pathway plays a predominant role in migration of B cells into PanLN in NOD mice. Thus, specific blockage of alpha(4)beta(7) integrin/MAdCAM-1 adhesion pathway-mediated B cell migration may be a potential treatment for T1D., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Unlabelled: Periprosthetic fracture is an uncommon but typically complex complication of cemented THA usually treated operatively. It is a source of reduced function, subsequent morbidity, and increased mortality. Previous studies may have underestimated the incidence of fracture through loss to followup or failure to use survivorship methodologies. The primary aim of this study was to use survivorship methodology to investigate the incidence of, and risk factors for fracture following primary arthroplasty. We examined a cohort of 6458 primary cemented femoral prostheses implanted during a 17-year period. One hundred twenty-four patients sustained fractures at the tip or below the femoral prosthesis. The incidence of fracture was 0.8% at 5 years and 3.5% at 10 years after primary implant. Patients older than 70 years had a 2.9 times greater risk of sustaining a subsequent fracture. There was no association between fracture and gender or implant type. These rates are higher than those reported for cemented arthroplasties. Older patients should be counseled regarding their higher risk of periprosthetic fracture, and additional research is required to elucidate the biologic mechanisms involved., Level of Evidence: Level II, retrospective prognostic study.

ABSTRACT Chromium is a common human contact allergen, but it is not known whether chromates cause contact hypersensitivity by immunological mechanisms similar to those induced by strong haptens. To understand the immunological events of contact hypersensitivity to chromates, we investigated whether and how chromate sensitization alters lymphocyte subsets in draining lymph nodes (DLNs), blood, and spleens in mice. BALB/c mice were sensitized by painting their ears with 0.5% potassium dichromate or vehicle alone on 3 consecutive days. Flow cytometric analysis of lymphocyte surface antigens showed that the chromate exposure significantly increased the percentage of B cells and decreased the percentages of T cells in the DLNs. This was accompanied by a relative increase in T cells and a relative decrease in B cells in peripheral blood. In contrast to the chromate, sodium dodecyl sulfate (a skin irritant) did not affect B cells or T cells in the three compartments. Moreover, sensitization to the chromate led to dose-dependent decreases in the percentages of CD4(+) T cells and CD8(+) T cells in the DLNs. However, CD4(+) and CD8(+) memory T cells were significantly increased in the blood and DLNs of the chromate-sensitized mice. Additionally, the percentage of B cells in the DLNs but not blood was dose-dependently increased in the chromate-sensitized mice. Histologically, B-cell areas were dramatically enlarged in the DLNs of the chromate-sensitized mice. Thus, this report provides basic information to further elucidate the role of individual lymphocyte subsets in contact hypersensitivity to chromates.

The results of 41 consecutive total knee replacements performed on morbidly obese patients with a body mass index > 40 kg/m(2), were compared with a matched group of 41 similar procedures carried out in non-obese patients (body mass index < 30 kg/m(2)). The groups were matched for age, gender, diagnosis, type of prosthesis, laterality and pre-operative Knee Society Score. We prospectively followed up the patients for a mean of 38.5 months (6 to 66). No patients were lost to follow-up. At less than four years after operation, the results were worse in the morbidly obese group compared with the non-obese, as demonstrated by inferior Knee Society Scores (mean knee score 85.7 and 90.5 respectively, p = 0.08; mean function score 75.6 and 83.4, p = 0.01), a higher incidence of radiolucent lines on post-operative radiographs (29% and 7%, respectively, p = 0.02), a higher rate of complications (32% and 0%, respectively, p = 0.001) and inferior survivorship using revision and pain as end-points (72.3% and 97.6%, respectively, p = 0.02). Patients with a body mass index > 40 kg/m(2) should be advised to lose weight prior to total knee replacement and to maintain weight reduction. They should also be counselled regarding the inferior results which may occur if they do not lose weight before surgery.

There are few direct comparative studies evaluating results after unicompartmental knee arthroplasty and total knee arthroplasty. We determined the active range of motion, Knee Society score, and 5-year survivorship rate after 54 consecutive unilateral unicompartmental knee arthroplasties compared with a matched group of 54 unilateral total knee arthroplasties. The two groups of patients were matched for age, gender, body mass index, preoperative active range of movement, and preoperative Knee Society scores. All patients had osteoarthritis of the knee. Patients were assessed prospectively at 6, 18, 36, and 60 months postoperatively, and the mean followup was 59 months in both groups. The mean postoperative active range of motion was greater after unicompartmental knee arthroplasty, but there were no differences in the overall Knee Society knee and function scores. The 5-year survivorship rate based on revision for any reason was 88% for unicompartmental knee arthroplasty and 100% for total knee arthroplasty. The worst case 5-year survivorship rate, assuming all patients lost to followup had revision surgery, was 85% for unicompartmental knee arthroplasty and 98% for total knee arthroplasty. Total knee arthroplasty was a more reliable procedure. Midterm clinical outcomes were similar for both procedures, but the complication rate may be greater for unicompartmental knee arthroplasty.

A total of 370 consecutive primary total knee replacements performed for osteoarthritis were followed up prospectively at 6, 18, 36 and 60 months. The Knee Society score and complications (perioperative mortality, superficial and deep wound infection, deep-vein thrombosis and revision rate) were recorded. By dividing the study sample into subgroups based on the body mass index overall, the body mass index in female patients and the absolute body-weight. The outcome in obese and non-obese patients was compared. A repeated measures analysis of variance showed no difference in the Knee Society score between the subgroups. There was no statistically-significant difference in the complication rates for the subgroups studied. Obesity did not influence the clinical outcome five years after total knee replacement.

The layering properties of ethane on MgO(100) were measured between 91 and 144 K using high-resolution adsorption isotherms. In contrast to previous studies, the results demonstrate that only three layers are formed. The thermodynamic functions derived from the data (isosteric heat, differential enthalpy, and entropy of adsorption) compare well with literature values and show a steady trend toward the bulk properties as the number of layers increased. Phase transitions for two of the layers were identified by monitoring the changes in the two-dimensional isothermal compressibility as a function of chemical potential. Both of these phase transitions occur at approximately 127 K and within 1 K of each other. Through the use of neutron diffraction, it is possible to identify at least one solid surface phase that melts at approximately 75 K. The transition at 127 K is therefore a transition between a liquidlike phase and a hyper-critical fluid. A comparison is made between the present data and our recent study of methane on MgO.

We report synthesis of nanowires and nanoribbons of the charge-density-wave conductor NbSe(3) through direct reaction of Nb and Se powders. The transverse dimension of the obtained nanostructures, as identified with scanning/transmission electron microscopy, ranges from 20 to 700 nm. X-ray and selected area electron diffraction analyses indicate that these nanowires and nanoribbons are single crystalline. Four-probe resistivity measurements confirm the expected charge-density-wave transitions, and furthermore, we find significant enhancement in the depinning threshold fields, which we attribute to a confinement effect.

Green rusts are mixed Fe(II)/Fe(III) hydroxides that are found in many suboxic environments where they are believed to play a central role in the biogeochemical cycling of iron. X-ray absorption fine structure analysis of hydroxysulfate green rust suspensions spiked with aqueous solutions of AgCH(3)COO, AuCl(n)(OH)(4-n), CuCl(2), or HgCl(2) showed that Ag(I), Au(III), Cu(II), and Hg(II) were readily reduced to Ag(0), Au(0), Cu(0), and Hg(0). Imaging of the resulting solids from the Ag(I)-, Au(III)-, and Cu(II)-amended green rust suspensions by transmission electron microscopy indicated the formation of submicron-sized particles of Ag(0), Au(0), and Cu(0). The facile reduction of Ag(I), Au(III), Cu(II), and Hg(II) to Ag(0), Au(0), Cu(0), and Hg(0), respectively, by green rust suggests that the presence of green rusts in suboxic soils and sediments can have a significant impact on the biogeochemistry of silver, gold, copper, and mercury, particularly with respect to their mobility.

This study was designed to assess the impact of gait analysis on the treatment of patients with cerebral palsy. One hundred two ambulant patients with cerebral palsy were assessed clinically and with gait analysis. Separate treatment proposals for each patient were recorded after clinical examination and after gait analysis. The results of the two methods of assessment were compared. After clinical assessment, 71 of the 102 patients evaluated were recommended for a surgical procedure and 31 for nonoperative treatment. After gait analysis, the indications for treatment were confirmed in 91 cases (89%). Clinical assessment by the same orthopedic surgeon was in close agreement with gait analysis in identifying an indication for surgery. There was less agreement in the type or level of operation recommended. Gait analysis altered the decision in 106 of 267 operations (40%). There was good agreement for bone surgery, suggesting that clinical evaluation of torsional problems was fairly reliable. The poorer agreement seen for soft tissue operations probably reflects the difficulties in assessing tone-related problems in these patients clinically. This study confirms the value of gait analysis for decision-making in cerebral palsy.

Green rusts, which are mixed ferrous/ferric hydroxides, are found in many suboxic environments and are believed to play a central role in the biogeochemistry of Fe. Analysis by U LIII-edge X-ray absorption near edge spectroscopy of aqueous green rust suspensions spiked with uranyl (U(VI)) showed that U(VI) was readily reduced to U(IV) by green rust The extended X-ray absorption fine structure (EXAFS) date for uranium reduced by green rust indicate the formation of a UO2 phase. A theoretical model based on the crystal structure of UO2 was generated by using FEFF7 and fitted to the data for the UO2 standard and the uranium in the green rust samples. The model fits indicate that the number of nearest-neighbor uranium atoms decreases from 12 for the UO2 structure to 5.4 forthe uranium-green rust sample. With an assumed four near-neighbor uranium atoms per uranium atom on the surface of UO2, the best-fit value for the average number of uranium atoms indicates UO2 particles with an average diameter of 1.7 +/- 0.6 nm. The formation of nanometer-scale particles of UO2, suggested by the modeling of the EXAFS data, was confirmed by high-resolution transmission electron microscopy, which showed discrete particles (approximately 2-9 nm in diameter) of crystalline UO2. Our results clearly indicate that U(VI) (as soluble uranyl ion) is readily reduced by green rust to U(IV) in the form of relatively insoluble UO2 nanoparticles, suggesting that the presence of green rusts in the subsurface may have significant effects on the mobility of uranium, particularly under iron-reducing conditions.

In a series of 150 consecutive patients with unstable fractures of the pelvis, angiography was performed in 23 (15%) who had uncontrolled hypotension. There were three anteroposterior compression (APC), eight lateral compression (LC) and 12 vertical shear (VS) injuries. Arterial sources of haemorrhage were identified in 18 (78%) patients and embolisation was performed. Angiography was required in 28% of VS injuries. The morphology of the fracture was not a reliable guide to the associated vascular injury. Ten (43%) patients died, of whom six had had angiography as the first therapeutic intervention. Five of these had a fracture which was associated with an increase in pelvic volume (APC or VS) which could have been stabilised by an external fixator. Based on our findings we recommend skeletal stabilisation and, if indicated, laparotomy to deal with sources of intraperitoneal blood loss before pelvic angiography. Embolisation of pelvic arterial bleeding is a worthwhile procedure in patients with hypotension which is unresponsive to these interventions.

The localization of excitons on quantum-dot-like compositional fluctuations has been observed in temperature-dependent near-field magnetophotoluminescence spectra of InGaAsN. Localization is driven by the giant bowing parameter of these alloys and manifests itself by the appearance of ultranarrow lines (half-width <1 meV) at temperatures below 70 K. We show how near-field optical scanning microscopy can be used for the estimation of the size, density, and nitrogen excess of individual compositional fluctuations (clusters), thus revealing random versus phase-separation effects in the distribution of nitrogen.

In a consecutive series of 498 patients with 528 fractures of the femur treated by conventional interlocking intramedullary nailing, 14 fractures of the femoral neck (2.7%) occurred in 13 patients. The fracture of the hip was not apparent either before operation or on the immediate postoperative radiographs. It was diagnosed in the first two weeks after operation in three patients and after three months in the remainder. Age over 60 years at the time of the femoral fracture and female gender were significantly predictive of hip fracture on bivariate logistic regression analysis, but on multivariate analysis only the location of the original fracture in the proximal third of the femur (p = 0.0022, odds ratio = 6.96, 95% CI 2.01 to 24.14), low-energy transfer (p = 0.0264, odds ratio = 15.56, 95% CI 1.38 to 75.48) and the severity of osteopenia on radiographs (p = 0.0128, odds ratio = 7.55, 95% CI 1.54 to 37.07) were significant independent predictors of later fracture. Five of the 19 women aged over 60 years, who sustained an osteoporotic proximal diaphyseal fracture of the femur during a simple fall, subsequently developed a fracture of the neck. Eleven of the hip fractures were displaced and intracapsular and, in view of the advanced age of most of these patients, were usually treated by replacement arthroplasty. Reduction and internal fixation was used to treat the remaining three intertrochanteric fractures. Three patients developed complications requiring further surgery; five died within two years of their fracture.

Background: Acute appendicitis remains problematic for emergency clinicians. A rapid and definitive test is needed for detecting acute appendicitis before surgical intervention. The purpose of this clinical trial was to determine the efficacy of Tc-99m-labeled intact polyvalent human immune globulin (Tc-99m IgG) in the evaluation of acute appendicitis., Study Design: Thirty-five patients with clinically suspected acute appendicitis were evaluated with Tc-99m IgG. After the intravenous injection of 25 mCi (92.5 MBq) of Tc-99m IgG, anterior flow, single photon emission computerized tomography (SPECT) and planar delayed images of the abdomen were obtained. Any abnormal focal uptake of Tc-99m IgG in the right lower quadrant was considered to be a positive scan., Results: Twenty-one patients with a positive Tc-99m IgG scan underwent laparotomy and were found to have acute appendicitis. Of the 14 patients who had negative scans, 7 underwent surgery. In this series, Tc-99m IgG study yielded 21 true-positive, 12 true-negative, and 2 false-negative results with a sensitivity, specificity, and accuracy of 91%, 100%, and 94%, respectively. The positive and negative predictive values were 100% and 86%, respectively. There were no false-positive results., Conclusions: Tc-99m IgG scintigraphy can provide the clinicians a simple, rapid, and definitive test for the diagnosis of acute appendicitis.

The Saint Joseph's Hospital Pharmacy-Nursing Committee sees a long list of pharmacy-nursing and drug distribution system problems still to be addressed and has no worry about running out of new business. In fact, increasing controlled substances accountability, creating a more reliable and timely process for moving intravenous fluid pumps through the inpatient system, and implementing a pharmacy-based, patient-controlled analgesia program across all of the hospitals' wards are three major issues now being addressed by the committee. At Saint Joseph's Hospital there is not a lot of unnecessary handwringing or undue stress over major pharmacy-nursing issues. Issues do exist, but there is also an experienced Pharmacy-Nursing Committee with a good track record of being able to resolve major issues. The committee takes on problems in a healthy and confident atmosphere of trust in both profession's skills and competencies. There is a respectful knowledge of each discipline's professional responsibilities and a full awareness that a quality patient drug system requires pharmacy and nursing elements working closely together. Wrestling with the heavy, modern-day, hospital pharmacy-nursing drug distribution system issues at this facility actually can be fun as a result of the confidence, camaraderie, and empathy that exists within the Pharmacy-Nursing Committee.

Early and late germinating classes of seedlings of a population of Viola blanda were censused for three years. Seedlings germinating later had a significantly higher probability of death, especially during a period of relatively high mortality three years after germination. Later germinating seedlings were consistently smaller than earlier germinating seedlings. Mortality was size-dependent and concentrated among smaller individuals. It is hypothesized that the effect of germination time on mortality three years later is mediated through differential growth.

Egg-laying females of the legume-feeding butterfly Colias philodice eriphyle were observed within a high-altitude study site during 1977 and 1978. Average oviposition selectivity showed two pattern sof seasonal variation. First, second brood females laid eggs more frequently after alighting upon hostplants than did first brood females in both years. Second, a consistent decline in post-alighting oviposition probability near the end of the second brood corresponded with a dramatic decrease in the water content of hostplant foliage near the end of the dry summer season. In addition to seasonal variation in oviposition behavior, individual females landed and oviposited upon widely varying sets of legume hostplant species. By sampling hostplant abundances along the flightpaths of observed females, we show that individuals varied in their tendency to land upon different hostplants. Females tended to specialize upon one or two species, at least in the short term, and the pattern of oligophagy for the population as a whole is partly generated by variation in the host-seeking behavior of individual females.

Lindeman's classic paper on energy flow in ecosystems was initially rejected for publication in Ecology. Reviewers felt there were insufficient data to support the theoretical model and that theoretical essays were inappropriate for Ecology. The paper was subsequently accepted by Thomas Park, the zoological editor, after correspondence with G. Evelyn Hutchinson who indicated the importance of theory in the development of ecology.

Egg-laying females of the legume-feeding butterfly Colias philodice eriphyle were observed within a high-altitude study site during 1977 and 1978. Average oviposition selectivity showed two patterns of seasonal variation. First, second-brood females laid eggs more frequently after alighting upon hostplants than did first-brood females in both years. Second, a consistent decline in post-alighting oviposition probability near the end of the second brood corresponded with a dramatic decrease in the water content of hostplant foliage near the end of the dry summer season. In addition to seasonal variation in oviposition behavior, individual females landed and oviposited upon widely varying sets of legume hostplant species. By sampling hostplant abundances along the flightpaths of observed females, we show that individuals varied in their tendency to land upon different hostplants. Females tended to specialize upon one or two species, at least in the short term, and the pattern of oligophagy for the population as a whole is partly generated by variation in the host-seeking behavior of individual females.