447 research outputs found
Pneumoperitoneum, pneumoretroperitoneum, pneumomediastinum and extensive subcutaneous emphysema in a patient with ulcerative colitis: a case report.
Abstract INTRODUCTION:
Pneumo-mediastinum and subcutaneous emphysema are rare presentations of lower gastrointestinal tract perforation. PRESENTATION OF CASE:
We are presenting the case of a middle aged man diagnosed with UC who presented with dyspnea and subcutaneous emphysema, attributed to multiple perforations including the stomach and colon. CASE DISCUSSION:
Patients with ulcerative colitis (UC) are at an increased risk of perforations due to friability of colonic mucosa given the chronic inflammation and relapsing flares. Chronic use of steroids further predisposes to stress ulcers. These pathologies sometimes coexist and identification of each is crucial for the appropriate treatment plan. CONCLUSION:
The case allows for a learning opportunity focusing on coexisting pathologies which may be differentiated based on anatomical knowledge and patient presentation.
Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserve
N,N′-[1,3-Phenylenebis(methylÂene)]dibenzeneÂsulfonamide
The complete molÂecule of the title compound, C20H20N2O4S2, is generated by crystallographic twofold symmetry, with two C atoms lying on the rotation axis. The dihedral angle between the central benzene ring and the pendant ring is 68.42 (6)° and the dihedral angle between the pendant rings is 45.11 (5)°. The torsion angles for the C—S—N—C and S—N—C—C fragments are −73.22 (15) and −150.45 (13)°, respectively. In the crystal, molÂecules are linked by N—H⋯O hydrogen bonds, generating corrugated (001) sheets. Aromatic π–π stacking [centroid–centroid separation = 3.8925 (12) and 3.9777 (12) Å] and weak C—H⋯O interÂactions also occur
N,N′-Diethyl-N,N′-[1,3-phenyleneÂbis(methylÂene)]dibenzeneÂsulfonamide
In the title compound, C24H28N2O4S2, the dihedral angles between the central benzene ring and the pendant rings are 77.44 (11) and 79.23 (10)°, and the dihedral angle between the pendant rings is 23.31 (12)°. Both sulfonamide groups project to the same side of the central benzene ring and the molÂecule has approximate non-crystallographic mirror symmetry. One of the ethyl side chains is disordered over two sets of sites in a 0.526 (14):0.474 (14) ratio. In the crystal, inversion dimers linked by pairs of weak C—H⋯O interÂactions occur, generating R
2
2(28) loops
Heterosexual HIV-1 infectiousness and antiretroviral use : systematic review of prospective studies of discordant couples
Background: Recent studies have estimated the reduction in HIV-1 infectiousness with antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials, accompanied by rigorous adherence counseling, are likely to overestimate the effectiveness of treatment-as-prevention in real-life settings.
Methods: We attempted to summarize the effect of ART on HIV transmission by undertaking a systematic review and meta-analysis of HIV-1 infectiousness per heterosexual partnership (incidence rate and cumulative incidence over study follow-up) estimated from prospective studies of discordant couples. We used random-effects Poisson regression models to obtain summary estimates. When possible, the analyses were further stratified by direction of transmission (man-to-woman or woman-to-man) and economic setting (high- or low-income countries). Potential causes of heterogeneity of estimates were explored through subgroup analyses.
Results: Fifty publications were included. Nine allowed comparison between ART and non-ART users within studies (ART-stratified studies), in which summary incidence rates were 3.6/100 person-years (95% confidence interval = 2.0-6.5) and 0.2/100 person-years (0.07-0.7) for non-ART- and ART-using couples, respectively (P < 0.001), constituting a 91% (79-96%) reduction in per-partner HIV-1 incidence rate with ART use. The 41 studies that did not stratify by ART use provided estimates with high levels of heterogeneity (I2 statistic) and few reported levels of ART use, making interpretation difficult. Nevertheless, estimates tended to be lower with ART use. Infectiousness tended to be higher for low-income than high-income settings, but there was no clear pattern by direction of transmission (man-to-woman and woman-to-man).
Conclusions: ART substantially reduces HIV-1 infectiousness within discordant couples, based on observational studies, and could play a major part in HIV-1 prevention efforts. However, the non-zero risk from partners receiving ART demonstrates that appropriate counseling and other risk-reduction strategies for discordant couples are still required. Additional estimates of ART effectiveness by adherence level from real-life settings will be important, especially for persons starting treatment early without symptoms
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Human value learning and representation reflects rational adaptation to task demands
Humans and other animals routinely make choices between goods of different value. Choices are often made within identifiable contexts, such that an efficient learner may represent values relative to their local context. However, if goods occur across multiple contexts, a relative value code can lead to irrational choice. In this case, an absolute context-independent value is preferable to a relative code. Here, we test the hypothesis that value representation is not fixed, but rationally adapted to context expectations. In two experiments, we manipulated participants‟ expectations about whether item values learned within local contexts would need to be subsequently compared across contexts. Despite identical learning experiences, the group whose expectations included choices across local contexts, went on to learn more absolute-like representation than the group whose expectations only covered fixed local contexts. Thus, human value representation is neither relative nor absolute, but efficiently and rationally tuned to task demands
Associations between significant head injury in male juveniles in prison in Scotland UK and cognitive function, disability and crime: a cross sectional study
Background:
Although the prevalence of head injury is estimated to be high in juveniles in prison, the extent of persisting disability is unknown and relationships with offending uncertain. This limited understanding makes it difficult to develop effective management strategies and interventions to improve health or reduce recidivism. This study investigates effects of significant head injury (SHI) on cognitive function, disability and offending in juvenile prisoners, and considers relationships with common comorbidities.
Methods:
This cross-sectional study recruited male juvenile prisoners in Scotland from Her Majesty’s Young Offenders Institute (HMYOI) Polmont (detaining approximately 305 of 310 male juveniles in prison in Scotland). To be included juveniles had to be 16 years or older, fluent in English, able to participate in assessment, provide informed consent and not have a severe acute disorder of cognition or communication. Head injury, cognition, disability, history of abuse, mental health and problematic substance use were assessed by interview and questionnaire.
Results:
We recruited 103 (34%) of 305 juvenile males in HMYOI Polmont. The sample was demographically representative of juvenile males in prisons for young offenders in Scotland. SHI was found in 82/103 (80%) and head injury repeated over long periods of time in 69/82 (85%). Disability was associated with SHI in 11/82 (13%) and was significantly associated with mental health problems, particularly anxiety. Group differences on cognitive tests were not found. However the SHI group reported poorer behavioural control on the Dysexecutive Questionnaire and were more often reported for incidents in prison than those without SHI. Characteristics of offending, including violence, did not differ between groups.
Conclusions:
Although SHI is highly prevalent in juvenile prisoners, associated disability was relatively uncommon. There was no evidence for differences in cognitive test performance or offending in juveniles with and without SHI. However, signs of poorer behavioural control and greater psychological distress in juveniles with SHI suggest that they may be at greater risk of recidivism and of potentially becoming lifelong offenders. This implies a need for remedial programmes for juvenile prisoners to take account of persisting effects of SHI on mental health and self-control and education and to improve their understanding of the effects of SHI reduce the likelihood of cumulative effects from further SHI
LoFT: Local Proxy Fine-tuning For Improving Transferability Of Adversarial Attacks Against Large Language Model
It has been shown that Large Language Model (LLM) alignments can be
circumvented by appending specially crafted attack suffixes with harmful
queries to elicit harmful responses. To conduct attacks against private target
models whose characterization is unknown, public models can be used as proxies
to fashion the attack, with successful attacks being transferred from public
proxies to private target models. The success rate of attack depends on how
closely the proxy model approximates the private model. We hypothesize that for
attacks to be transferrable, it is sufficient if the proxy can approximate the
target model in the neighborhood of the harmful query. Therefore, in this
paper, we propose \emph{Local Fine-Tuning (LoFT)}, \textit{i.e.}, fine-tuning
proxy models on similar queries that lie in the lexico-semantic neighborhood of
harmful queries to decrease the divergence between the proxy and target models.
First, we demonstrate three approaches to prompt private target models to
obtain similar queries given harmful queries. Next, we obtain data for local
fine-tuning by eliciting responses from target models for the generated similar
queries. Then, we optimize attack suffixes to generate attack prompts and
evaluate the impact of our local fine-tuning on the attack's success rate.
Experiments show that local fine-tuning of proxy models improves attack
transferability and increases attack success rate by , , and
(absolute) on target models ChatGPT, GPT-4, and Claude respectively
Nucleation of a sodium droplet on C60
We investigate theoretically the progressive coating of C60 by several sodium
atoms. Density functional calculations using a nonlocal functional are
performed for NaC60 and Na2C60 in various configurations. These data are used
to construct an empirical atomistic model in order to treat larger sizes in a
statistical and dynamical context. Fluctuating charges are incorporated to
account for charge transfer between sodium and carbon atoms. By performing
systematic global optimization in the size range 1<=n<=30, we find that Na_nC60
is homogeneously coated at small sizes, and that a growing droplet is formed
above n=>8. The separate effects of single ionization and thermalization are
also considered, as well as the changes due to a strong external electric
field. The present results are discussed in the light of various experimental
data.Comment: 17 pages, 10 figure
Interleukin 6 in autoimmune and inflammatory diseases: a personal memoir
In this review, the author discusses the research that led to the identification and characterization of interleukin 6 (IL-6), including his own experience isolating IL-6, and the roles this cytokine has on autoimmune and inflammatory diseases. The cDNAs encoding B-cell stimulatory factor 2 (BSF-2), interferon (IFN)-β2 and a 26-kDa protein were independently cloned in 1986, which in turn led to the identification of each. To resolve the confusing nomenclature, these identical molecules were named IL-6. Characterization of IL-6 revealed a multifunctional cytokine that is involved in not only immune responses but also hematopoiesis, inflammation, and bone metabolism. Moreover, IL-6 makes significant contributions to such autoimmune and inflammatory diseases as rheumatoid arthritis (RA)
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