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This article summarizes the results of controlled experiments in which flaked-stone points that varied in impact strength by a factor of almost three were shot at media that were increasingly inelastic and therefore likely to break the points. Broken tips were reworked if possible, and used again under the same conditions. Our results show that all damage to low impact-strength materials, especially obsidian, was generally catastrophic, and, consequently, these points could only rarely be reworked. The fact that low-strength stones were commonly used to make small arrowpoints suggests that reworking was not a primary concern for their designers. Furthermore, in those instances when broken tips could be reworked, their performance declined. In addition, reworking broken points also resulted in shapes that are uncommon in many arrowpoint assemblages. Our results suggest that the original design attributes of arrowpoints may have been less affected by reworking, and, consequently, may more accurately suggest temporal and behavioral associations.
We assessed the impact of personal protective equipment (PPE) doffing errors on healthcare worker (HCW) contamination with multidrug-resistant organisms (MDROs).
Prospective, observational study.
The study was conducted at 4 adult ICUs at 1 tertiary-care teaching hospital.
HCWs who cared for patients on contact precautions for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci, or multidrug-resistant gram-negative bacilli were enrolled. Samples were collected from standardized areas of patient body, garb sites, and high-touch environmental surfaces in patient rooms. HCW hands, gloves, PPE, and equipment were sampled before and after patient interaction. Research personnel observed PPE doffing and coded errors based on CDC guidelines.
We enrolled 125 HCWs; most were nurses (66.4%) or physicians (19.2%). During the study, 95 patients were on contact precautions for MRSA. Among 5,093 cultured sites (HCW, patient, environment), 652 (14.7%) yielded the target MDRO. Moreover, 45 HCWs (36%) were contaminated with the target MDRO after patient interactions, including 4 (3.2%) on hands and 38 (30.4%) on PPE. Overall, 49 HCWs (39.2%) made multiple doffing errors and were more likely to have contaminated clothes following a patient interaction (risk ratio [RR], 4.69; P = .04). All 4 HCWs with hand contamination made doffing errors. The risk of hand contamination was higher when gloves were removed before gowns during PPE doffing (RR, 11.76; P = .025).
When caring for patients on CP for MDROs, HCWs appear to have differential risk for hand contamination based on their method of doffing PPE. An intervention as simple as reinforcing the preferred order of doffing may reduce HCW contamination with MDROs.
Experimentally validated large eddy simulations were performed on two NACA0012 vanes at various lateral offsets to observe the transient effects of the near field interactions between two streamwise vortices. The vanes were separated in the streamwise direction, allowing the upstream vortex to impact on the downstream geometry. These vanes were evaluated at an angle of incidence of
and a Reynolds number of 70 000, with rear vane angle reversed to create a co-rotating or counter-rotating vortex pair. The downstream vortex merged with the upstream in the co-rotating condition, driven by the suppression of one of the tip vortices of the downstream vane. At close proximity to the pressure side, the vane elongated the upstream vortex, resulting in it being the weakened and merging into the downstream vortex. This produced a transient production of bifurcated vortices in the wake region. The downstream vortex of the co-rotating pair experienced faster meandering growth, with position oscillations equalising between the vortices. The position oscillation was determined to be responsible for statistical variance in the merging location, with variation in vortex separation causing the vortices at a single plane to merge and separate in a time-dependent manner. In the counter-rotating condition position oscillations were found to be larger, with higher growth, but less uniform periodicity. It was found that the circulation transfer between the vortices was linked to the magnitude of their separation, with high separation fluctuations weakening the upstream vortex and strengthening the downstream vortex. In the case of upstream vortex impingement on the downstream vane, the upstream vortex was found to bifurcate, with a four vortex system being formed by interactions with the shear layer. This eventually resulted in a single dominant vortex, which did not magnify its oscillation amplitudes as it travelled downstream due to the destruction of the interacting vortices.
Whitehouse's article posits several plausible hypotheses, but suffers from an unwarranted reliance on the importance of distinct social groups in the causation of self-sacrificing behavior. A focus on relationships between individual kin is better able to account for both the evolution of self-sacrifice and present forms of self-sacrifice. The practical importance of this point is discussed.
Culture-based studies, which focus on individual organisms, have implicated stethoscopes as potential vectors of nosocomial bacterial transmission. However, the full bacterial communities that contaminate in-use stethoscopes have not been investigated.
We used bacterial 16S rRNA gene deep-sequencing, analysis, and quantification to profile entire bacterial populations on stethoscopes in use in an intensive care unit (ICU), including practitioner stethoscopes, individual-use patient-room stethoscopes, and clean unused individual-use stethoscopes. Two additional sets of practitioner stethoscopes were sampled before and after cleaning using standardized or practitioner-preferred methods.
Bacterial contamination levels were highest on practitioner stethoscopes, followed by patient-room stethoscopes, whereas clean stethoscopes were indistinguishable from background controls. Bacterial communities on stethoscopes were complex, and community analysis by weighted UniFrac showed that physician and patient-room stethoscopes were indistinguishable and significantly different from clean stethoscopes and background controls. Genera relevant to healthcare-associated infections (HAIs) were common on practitioner stethoscopes, among which Staphylococcus was ubiquitous and had the highest relative abundance (6.8%–14% of contaminating bacterial sequences). Other HAI-related genera were also widespread although lower in abundance. Cleaning of practitioner stethoscopes resulted in a significant reduction in bacterial contamination levels, but these levels reached those of clean stethoscopes in only a few cases with either standardized or practitioner-preferred methods, and bacterial community composition did not significantly change.
Stethoscopes used in an ICU carry bacterial DNA reflecting complex microbial communities that include nosocomially important taxa. Commonly used cleaning practices reduce contamination but are only partially successful at modifying or eliminating these communities.
Electrically conducting substrates have shown much promise as neuronal scaffolds and in other biologic and biomedical applications where a smart and electrically interactive material is needed. Most materials that are inherently conducting are not suitable for biomedical applications and lack biocompatibility or biostability. On the other hand, biologically stable and compatible materials must first be manipulated, modified, and treated in order to impart the necessary electrical conductivity to the material. Here, the authors have investigated the response of PC-12 cells to two types of conducting carbon-based aerogels with different surface roughness. Results show that carbon-based aerogels support cell adhesion, proliferation, and neurite extension. The effects of surface roughness have also been investigated.
OBJECTIVES/SPECIFIC AIMS: Despite aggressive chemotherapy, surgical resection, and radiation therapy, glioblastoma remains almost universally fatal. In a pilot, randomized, and blinded clinical trial, we recently demonstrated that administration of RNA-loaded DC vaccines was associated with significantly improved progression-free and overall survival in patients with glioblastoma (Mitchell et al., Nature, 2015). Furthermore, clinical outcomes correlated with DC migration to vaccine-site draining lymph nodes measured by Indium-111 labeling of RNA-loaded DCs and SPECT/CT imaging. Although these studies demonstrated that tracking DC migration may be an important clinical biomarker for response to DC vaccination, the complexity and regulatory requirements associated with nuclear labelling to track DC migration limits widespread application of this technique. We have therefore developed RNA-loaded magnetic nanoparticles (RNA-NPs) to enhance DC migration to LNs and track that migration with a widely available imaging modality (i.e., MRI). METHODS/STUDY POPULATION: Cationic liposomes were loaded with iron oxide nanoparticles with or without cholesterol. The resulting nanoparticles were complexed with RNA and used to transfect DCs ex vivo. RNA-NP-loaded DsRed+ DCs were then injected intradermally into mice and tracked noninvasively with T2-weighted 11T MRI before excision and quantification with flow cytometry. RESULTS/ANTICIPATED RESULTS: In vitro experiments demonstrate that iron oxide loading does not reduce RNA-NP-mediated transfection of DCs. Additionally, replacement of cationic lipids with cholesterol increased RNA-NP transfection of the DC2.4 cell line and enhanced the T cell stimulatory capacity of treated bone marrow-derived dendritic cells (BMDCs). Compared to electroporation, RNA-NPs enhanced DC migration to lymph nodes and reduced T2 MRI intensity in DC-bearing lymph nodes. DISCUSSION/SIGNIFICANCE OF IMPACT: This data suggests that iron oxide-loaded RNA-NPs enable noninvasive cell tracking with MRI and enhance DC migration to lymph nodes. We have further shown that inclusion of cholesterol in RNA-NPs augments the stimulatory capacity of transfected DCs. Future work will consider effects of RNA-NPs on antitumor immune responses and the utility of MRI-detected DC migration as a biomarker of vaccine efficacy.
Insomnia is effectively treated with online Cognitive Behavioral Therapy for Insomnia (CBT-I). Previous research has suggested the effects might not be limited to sleep and insomnia severity, but also apply to depressive symptoms. Results, however, are mixed.
In this randomized controlled trial we investigated the effects of guided online CBT-I on depression and insomnia in people suffering from symptoms of both. Participants (n = 104) with clinical insomnia and at least subclinical depression levels were randomized to (1) guided online CBT-I and sleep diary monitoring (i-Sleep) or (2) control group (sleep diary monitoring only). The primary outcome was the severity of depressive symptoms (Patient Health Questionnaire-9 without sleep item; PHQ-WS). Secondary outcomes were insomnia severity, sleep diary parameters, fatigue, daytime consequences of insomnia, anxiety, and perseverative thinking.
At post-test, participants in the i-Sleep condition reported significantly less depressive symptoms (PHQ-WS) compared with participants in the sleep-diary condition (d = 0.76). Large significant effects were also observed for insomnia severity (d = 2.36), most sleep diary parameters, daytime consequences of insomnia, anxiety, and perseverative thinking. Effects were maintained at 3 and 6 month follow-up. We did not find significant post-test effects on fatigue or total sleep time.
Findings indicate that guided online CBT-I is not only effective for insomnia complaints but also for depressive symptoms. The effects are large and comparable with those of depression therapy. Clinical trial registration number: NTR6049 (Netherlands Trial Register).
We hypothesized that a computerized clinical decision support tool for Clostridium difficile testing would reduce unnecessary inpatient tests, resulting in fewer laboratory-identified events. Census-adjusted interrupted time-series analyses demonstrated significant reductions of 41% fewer tests and 31% fewer hospital-onset C. difficile infection laboratory-identified events following this intervention.
Recently in vitro and in situ techniques have been used for assessing forage nutritive value for ruminants instead of laborious in vivo trials. Although, Blummel and Ørskov (1993) have shown that an in vitro gas production technique gives reliable estimates of forage nutritive value, whether the estimates could be correlated with in situ degradation are not well established. There is little known about the differences in degradation characteristics of neutral-detergent fibre (NDF) and cellular contents (CC: soluble carbohydrates, lipids and crude protein) in the rumen, and also about the relationships between component degradation rate in the rumen and gas production rate for different forages. This is because most in situ kinetic studies have followed the disappearance of insoluble cell wall constituents and comparative studies of in vitro and in situ estimates was not performed sufficiently.
The objective of this experiment was to investigate the relationship between in situ degradation of forage components and in vitro gas production rate for the three forages.
We study changes in farming in the Marcellus region associated with unconventional natural gas drilling activity. Due to concerns raised by the popular press, we consider 18 different county-level agricultural variables. While we find no significant changes in the number of farms or land in farms in drilling counties relative to non-drilling counties, there is an increase in median farm sizes, indicating potential consolidation in drilling counties. Despite anecdotal evidence suggesting a transition away from dairy farming to either beef or hay production, we find no support for this at the county level.
The mammary gland of lactating ruminants (Guinard & Rulquin 1994) does not appear to extract sufficient quantities of free amino acids (AA) to account for their output as milk protein. Based upon application of a precursor (blood or plasma free AA):product (casein) labelling technique (Backwell et al. 1996) in goats, results suggest that blood peptides or proteins taken up by the gland probably account for this deficit. However, the deficiency appears to be alleviated when supplemental protein or AA are infused (Guinard & Rulquin 1994), suggesting that uptake of peptide bound AA is reduced while that of the free AA is increased. The objective of the current study was to corroborate these findings, thus the precursonproduct labelling technique was applied in lactating goats to determine whether arterial free phenylalanine supply affects the contribution of peptide bound phenylalanine and tyrosine to casein synthesis and compare the results to the net uptake (NU) method.