1,149 research outputs found
Nanostructured Aerosol Particles: Fabrication, Pulmonary Drug Delivery, and Controlled Release
Pulmonary drug delivery is the preferred route of administration in the treatment of respiratory diseases and some nonrespiratory diseases. Recent research has focused on developing structurally stable high-dosage drug delivery systems without premature release. To maximize the deposition in the desired lung regions, several factors must be considered in the formulation. The special issue includes seven papers deal with aerosol-assisted fabrication of nanostructured particles, aerosol deposition, nanoparticles pulmonary exposure, and controlled release
Revealing the Blind Spot of Sentence Encoder Evaluation by HEROS
Existing sentence textual similarity benchmark datasets only use a single
number to summarize how similar the sentence encoder's decision is to humans'.
However, it is unclear what kind of sentence pairs a sentence encoder (SE)
would consider similar. Moreover, existing SE benchmarks mainly consider
sentence pairs with low lexical overlap, so it is unclear how the SEs behave
when two sentences have high lexical overlap. We introduce a high-quality SE
diagnostic dataset, HEROS. HEROS is constructed by transforming an original
sentence into a new sentence based on certain rules to form a \textit{minimal
pair}, and the minimal pair has high lexical overlaps. The rules include
replacing a word with a synonym, an antonym, a typo, a random word, and
converting the original sentence into its negation. Different rules yield
different subsets of HEROS. By systematically comparing the performance of over
60 supervised and unsupervised SEs on HEROS, we reveal that most unsupervised
sentence encoders are insensitive to negation. We find the datasets used to
train the SE are the main determinants of what kind of sentence pairs an SE
considers similar. We also show that even if two SEs have similar performance
on STS benchmarks, they can have very different behavior on HEROS. Our result
reveals the blind spot of traditional STS benchmarks when evaluating SEs.Comment: ACL 2023 repl4nlp (representation learning for NLP) workshop poster
paper. Dataset at https://huggingface.co/datasets/dcml0714/Hero
Characterization of Aerosols Containing Microcystin
Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 μm. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ
Aerosol-Assisted Synthesis of Monodisperse Single-Crystalline α-Cristobalite Nanospheres
Monodisperse single-crystalline α-cristobalite nanospheres have been synthesized by hydrocarbon-pyrolysis-induced carbon deposition on amorphous silica aerosol nanoparticles, devitrification of the coated silica at high temperature, and subsequent carbon removal by oxidation. The nanosphere size can be well controlled by tuning the size of the colloidal silica precursor. Uniform, high-purity nanocrystalline α-cristobalite is important for catalysis, nanocomposites, advanced polishing, and understanding silica nanotoxicology
Heparinization on pericardial substitutes can reduce adhesion and epicardial inflammation in the dog
AbstractObjective: Primary concerns about currently available pericardial substitutes include adhesion and epicardial reaction. The purpose of this study is to evaluate host reaction to pericardial substitutes with and without incorporating slow heparin release. Methods: To avoid biologic variation among these pericardial patches, we made a composite of six membranes. The composite membrane consisted of epoxy-fixed patches with (1) or without (2) ionically bound heparin, a glutaraldehyde-fixed patch with (3) or without (4) ionically bound heparin, an expanded polytetrafluoroethylene patch (5), and a polyester polymeric patch (6). Ten recipient dogs weighing from 12 to 19 kg (mean 13.6 kg) were used to assess the composite membranes as pericardial substitutes. The implanted composite membranes were retrieved 1 week (one dog), 2 weeks (one dog), 4 weeks (one dog), 8 weeks (one dog), and 12 weeks (six dogs) after implantation. Results: Overall, the synthetic patches had a more notable inflammatory reaction than the biologic patches with or without ionically bound heparin. The heparin-bound patches caused significantly less inflammation than their nonheparinized counterparts. The heparinized porcine patches cross-linked with different compounds were found to have less fibrous formation than the nonheparinized patches and the synthetic patches. Conclusions: Heparinized pericardial substitutes may cause less adhesion and inflammatory reaction than nonheparinized material. (J Thorac Cardiovasc Surg 1998;115:1111-20
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Whole exome sequencing identifies genetic markers of enterovirus susceptibility in East Asians.
INTRODUCTION: Following acute enterovirus (EV) infection, outcomes vary based on factors like the immune response, viral cell entry receptor expression levels, tissue tropism, and genetic factors of both the host and virus. While most individuals exhibit mild, self-limited symptoms, others may suffer severe complications or prolonged infections that can lead to autoimmune disorders. METHODS: To elucidate host responses to EV infection, we performed whole exome sequencing on blood samples from both infected and uninfected individuals. Our initial focus was on genes encoding EV entry receptors-PSGL-1, SCARB2, and ANAXA2 for EV-A71, and CD155 for poliovirus-and on host genes ACBD3 and PI4KÎ’, crucial for EV replication. RESULTS: Although no specific genetic variants directly associated with EV infection were identified, we discovered 118 variants across 116 genes enriched in East Asian populations through multi-layered variant filtering. These variants were further analyzed for their potential impacts on organs, biological processes, and molecular pathways. Phenome-wide association studies were conducted to refine our understanding of their contributions to EV infection susceptibility. DISCUSSION: Our findings aim to develop a predictive panel based on these 118 variants, which could help susceptible individuals during EV outbreaks, guiding targeted clinical interventions and preventative strategies
Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake
We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses), but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L) in the water and (<0.1 ng/m3) in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L). Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins
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