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Accurate and rapid point-of-care tissue and microbiome sampling is critical for early detection of cancers and infectious diseases and often result in effective early intervention and prevention of disease spread. In particular, the low prevalence of Barrett's and gastric premalignancy in the Western world makes population-based endoscopic screening unfeasible and cost-ineffective. Herein, we report a method that may be useful for prescreening the general population in a minimally invasive way using a swallowable, re-expandable, ultra-absorbable, and retrievable nanofiber cuboid and sphere produced by electrospinning, gas-foaming, coating, and crosslinking. The water absorption capacity of the cuboid- and sphere-shaped nanofiber objects is shown ∼6000% and ∼2000% of their dry mass. In contrast, unexpanded semicircular and square nanofiber membranes showed500% of their dry mass. Moreover, the swallowable sphere and cuboid were able to collect and release more bacteria, viruses, and cells/tissues from solutions as compared with unexpanded scaffolds. In addition to that, an expanded sphere shows higher cell collection capacity from the esophagus inner wall as compared with the unexpanded nanofiber membrane. Taken together, the nanofiber capsules developed in this study could provide a minimally invasive method of collecting biological samples from the duodenal, gastric, esophagus, and oropharyngeal sites, potentially leading to timely and accurate diagnosis of many diseases. STATEMENT OF SIGNIFICANCE: Recently, minimally invasive technologies have gained much attention in tissue engineering and disease diagnosis. In this study, we engineered a swallowable and retrievable electrospun nanofiber capsule serving as collection device to collect specimens from internal organs in a minimally invasive manner. The sample collection device could be an alternative endoscopy to collect the samples from internal organs like jejunum, stomach, esophagus, and oropharynx without any sedation. The newly engineered nanofiber capsule could be used to collect, bacteria, virus, fluids, and cells from the abovementioned internal organs. In addition, the biocompatible and biodegradable nanofiber capsule on a string could exhibit a great sample collection capacity for the primary screening of Barret Esophagus, acid reflux, SARS-COVID-19, Helicobacter pylori, and gastric cancer.

Liquid metal–elastomer composite is a promising soft conductor for skin-interfaced bioelectronics, soft robots, and others due to its large stretchability, ultrasoftness, high electrical conductivity, and mechanical-electrical decoupling. However, it often suffers from deformation-induced leakage, which can smear skin, deteriorate device performance, and cause circuit shorting. Besides, antimicrobial property is desirable in soft conductors to minimize microbial infections. Here, we report phase separation–based synthesis of porous liquid metal–elastomer composites with high leakage resistance and antimicrobial property, together with large stretchability, tissue-like compliance, high and stable electrical conductivity over deformation, high breathability, and magnetic resonance imaging compatibility. The porous structures can minimize leakage through damping effects and lower percolation thresholds to reduce liquid metal usage. In addition, epsilon polylysine is loaded into elastic matrices during phase separation to provide antimicrobial property. The enabled skin-interfaced bioelectronics can monitor cardiac electrical and mechanical activities and offer electrical stimulations in a mechanically imperceptible and electrically stable manner even during motions.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and resulting COVID-19 (coronavirus disease 2019) pandemic have required mass diagnostic testing, often taking place in testing sites within hospitals, clinics, or at satellite locations. To establish the potential of SARS-CoV-2 aerosol transmission and to identify junctures during testing that result in increased viral exposure, aerosol and surface samples were examined for the presence of SARS-CoV-2 RNA from locations within Nebraska Medicine COVID-19 testing and vaccine clinics. Aerosols containing SARS-CoV-2 RNA detected within clinics suggest viral shedding from infected individuals. SARS-CoV-2 RNA detection in aerosol samples was shown to correlate with clinic operation and patient infection, as well as with community infection findings. Additionally, SARS-CoV-2 RNA was detected in surface samples collected from clinics. The presence of SARS-CoV-2 RNA in aerosols in these clinics supports the continued use of respiratory protection and sanitization practices for healthcare workers, and other workers with public facing occupations.

Background Aerosol transmission of COVID-19 is the subject of ongoing policy debate. Characterizing aerosol produced by people with COVID-19 is critical to understanding the role of aerosols in transmission. Objective We investigated the presence of virus in size-fractioned aerosols from six COVID-19 patients admitted into mixed acuity wards in April of 2020. Methods Size-fractionated aerosol samples and aerosol size distributions were collected from COVID-19 positive patients. Aerosol samples were analyzed for viral RNA, positive samples were cultured in Vero E6 cells. Serial RT-PCR of cells indicated samples where viral replication was likely occurring. Viral presence was also investigated by western blot and transmission electron microscopy (TEM). Results SARS-CoV-2 RNA was detected by rRT-PCR in all samples. Three samples confidently indicated the presence of viral replication, all of which were from collected sub-micron aerosol. Western blot indicated the presence of viral proteins in all but one of these samples, and intact virions were observed by TEM in one sample. Significance Observations of viral replication in the culture of submicron aerosol samples provides additional evidence that airborne transmission of COVID-19 is possible. These results support the use of efficient respiratory protection in both healthcare and by the public to limit transmission.

Airborne contaminants from fires containing nuclear waste represent significant health hazards and shape the design and operation of nuclear facilities. Much of the data used to formulate DOE-HDBK-...

Key Points Question Does weekly testing of kindergarten through 12th grade students and staff improve detection of SARS-CoV-2 infection and understanding of the epidemiology of SARS-CoV-2 in urban public school settings? Findings In this quality improvement study, weekly school-based saliva polymerase chain reaction testing at 3 urban public schools was associated with increased case detection among staff and students compared with symptom-based strategies, exceeding county-level case rates. SARS-CoV-2 was detected in school wastewater samples each week as well as air and surface samples from choir classrooms. Meaning This study suggests that routine SARS-CoV-2 testing may identify infected staff and students who are not identified through conventional case detection and may provide insight into disease burdens of undertested communities., Importance Scalable programs for school-based SARS-CoV-2 testing and surveillance are needed to guide in-person learning practices and inform risk assessments in kindergarten through 12th grade settings. Objectives To characterize SARS-CoV-2 infections in staff and students in an urban public school setting and evaluate test-based strategies to support ongoing risk assessment and mitigation for kindergarten through 12th grade in-person learning. Design, Setting, and Participants This pilot quality improvement program engaged 3 schools in Omaha, Nebraska, for weekly saliva polymerase chain reaction testing of staff and students participating in in-person learning over a 5-week period from November 9 to December 11, 2020. Wastewater, air, and surface samples were collected weekly and tested for SARS-CoV-2 RNA to evaluate surrogacy for case detection and interrogate transmission risk of in-building activities. Main Outcomes and Measures SARS-CoV-2 detection in saliva and environmental samples and risk factors for SARS-CoV-2 infection. Results A total of 2885 supervised, self-collected saliva samples were tested from 458 asymptomatic staff members (mean [SD] age, 42.9 [12.4] years; 303 women [66.2%]; 25 Black or African American [5.5%], 83 Hispanic [18.1%], 312 White [68.1%], and 35 other or not provided [7.6%]) and 315 students (mean age, 14.2 [0.7] years; 151 female students [48%]; 20 Black or African American [6.3%], 201 Hispanic [63.8%], 75 White [23.8%], and 19 other race or not provided [6.0%]). A total of 46 cases of SARS-CoV-2 (22 students and 24 staff members) were detected, representing an increase in cumulative case detection rates from 1.2% (12 of 1000) to 7.0% (70 of 1000) among students and from 2.1% (21 of 1000) to 5.3% (53 of 1000) among staff compared with conventional reporting mechanisms during the pilot period. SARS-CoV-2 RNA was detected in wastewater samples from all pilot schools as well as in air samples collected from 2 choir rooms. Sequencing of 21 viral genomes in saliva specimens demonstrated minimal clustering associated with 1 school. Geographical analysis of SARS-CoV-2 cases reported district-wide demonstrated higher community risk in zip codes proximal to the pilot schools. Conclusions and Relevance In this study of staff and students in 3 urban public schools in Omaha, Nebraska, weekly screening of asymptomatic staff and students by saliva polymerase chain reaction testing was associated with increased SARS-CoV-2 case detection, exceeding infection rates reported at the county level. Experiences differed among schools, and virus sequencing and geographical analyses suggested a dynamic interplay of school-based and community-derived transmission risk. Collectively, these findings provide insight into the performance and community value of test-based SARS-CoV-2 screening and surveillance strategies in the kindergarten through 12th grade educational setting., This quality improvement study characterizes SARS-CoV-2 infections in staff and students in an urban public school setting and evaluates test-based strategies to support ongoing risk assessment and mitigation for kindergarten through 12th grade in-person learning.

Biological aerosol particles have been studied in the laboratory for many decades to understand their roles in human health and disease and in environmental processes. These studies have used a var...

An advanced rotating aerosol chamber was developed to study the changes of fluorescence spectral profile and intensity, the viability and the quantitative polymerase chain reaction (qPCR) s...

Introduction Aeromedical evacuation (AE) is a challenging process, further complicated when a patient has a highly hazardous communicable disease (HHCD). We conducted a review of the literature to evaluate the processes and procedures utilized for safe AE high-level containment transport (AE-HLCT) of patients with HHCDs. Methods A literature search was performed in PubMed/MEDLINE (from 1966 through January 2019). Authors screened abstracts for inclusion criteria and full articles were reviewed if the abstract was deemed to contain information related to the aim. Results Our search criteria yielded 14 publications and were separated based upon publication dates, with the natural break point being the beginning of the 2013-2016 Ebola virus disease epidemic. Best practices and recommendations from identified articles are subdivided into pre-flight preparations, inflight operations, and post-flight procedures. Conclusions Limited peer-reviewed literature exists on AE-HLCT, including important aspects related to healthcare worker fatigue, alertness, shift scheduling, and clinical care performance. This hinders the sharing of best practices to inform evacuations and equip teams for future outbreaks. Despite the successful use of different aircraft and technologies, the unique nature of the mission opens the opportunity for greater coordination and development of consensus standards for AE-HLCT operations.

ImportanceScalable programs for school-based SARS-CoV-2 testing and surveillance are needed to guide in-person learning practices and inform risk assessments in K-12 settings.ObjectivesTo characterize SARS-CoV-2 infections in staff and students in an urban public school setting and evaluate test-based strategies to support ongoing risk assessment and mitigation for K-12 in-person learning.Design, Setting, and ParticipantsThe pilot program engaged three schools for weekly saliva PCR testing of staff and students participating in in-person learning over a 5-week period. Wastewater, air, and surface samples were collected weekly and tested for SARS-CoV-2 RNA to determine surrogacy for case detection and interrogate transmission risk of in-building activities.Main Outcomes and MeasuresSARS-CoV-2 detection in saliva and environmental samples and risk factors for SARS-CoV-2 infection.Results2,885 supervised self-collected saliva samples were tested from 773 asymptomatic staff and students during November and December, 2020. 46 cases (22 students, 24 staff) were detected, representing a 5.8- and 2.5-fold increase in case detection rates among students and staff, respectively, compared to conventional reporting mechanisms. SARS-CoV-2 RNA was detected in wastewater samples from all pilot schools, as well as in air samples collected from two choir rooms. Sequencing of 21 viral genomes in saliva specimens demonstrated minimal clustering associated with one school. Geographic analysis of SARS-CoV-2 cases reported district-wide demonstrated higher community risk in zip codes proximal to the pilot schools.Conclusions and RelevanceWeekly screening of asymptomatic staff and students by saliva PCR testing dramatically increased SARS-CoV-2 case detection in an urban public-school setting, exceeding infection rates reported at the county level. Experiences differed among schools, and virus sequencing and geographic analyses suggest a dynamic interplay of school-based and community-derived transmission risk. Environmental testing for SARS-CoV-2 RNA in air and surface samples enabled real-time risk assessment of in-school activities and allowed for interventions in choir classes. Wastewater testing demonstrated the utility of school building-level SARS-CoV-2 surveillance. Collectively, these findings provide insight into the performance and community value of test-based SARS-CoV-2 screening and surveillance strategies in the K-12 educational setting.KEY POINTSQuestionDo test-based programs reduce SARS-CoV-2 risk in K-12 schools?FindingsWeekly school-based saliva PCR testing at three urban public schools doubled case detection among staff and students over symptom-based strategies, exceeding county-level case rates. SARS-CoV-2 was detected in school wastewater samples each week, as well as air and surface samples related to choir classrooms.MeaningRoutine SARS-CoV-2 testing removes infected staff and students from school who are not identified through conventional case detection. With rigorous infection control and environmental monitoring, this helps mitigate risk during school operations. Furthermore, screening in K-12 schools may provide insight into disease burdens of undertested communities.

Following the COVID-19 outbreak, swabs for biological specimen collection were thrust to the forefront of healthcare materials. Swab sample collection and recovery are vital for reducing false negative diagnostic tests, early detection of pathogens, and harvesting DNA from limited biological samples. In this study, we report a new class of nanofiber swabs tipped with hierarchical 3D nanofiber objects produced by expanding electrospun membranes with a solids-of-revolution-inspired gas foaming technique. Nanofiber swabs significantly improve absorption and release of proteins, cells, bacteria, DNA, and viruses from solutions and surfaces. Implementation of nanofiber swabs in SARS-CoV-2 detection reduces the false negative rates at two viral concentrations and identifies SARS-CoV-2 at a 10× lower viral concentration compared to flocked and cotton swabs. The nanofiber swabs show great promise in improving test sensitivity, potentially leading to timely and accurate diagnosis of many diseases.

The COVID-19 pandemic has reintroduced questions regarding the potential risk of SARS-CoV-2 exposure amongst passengers on an aircraft. Quantifying risk with computational fluid dynamics models or contact tracing methods alone is challenging, as experimental results for inflight biological aerosols is lacking. Using fluorescent aerosol tracers and real time optical sensors, coupled with DNA-tagged tracers for aerosol deposition, we executed ground and inflight testing on Boeing 767 and 777 airframes.Analysis here represents tracer particles released from a simulated infected passenger, in multiple rows and seats, to determine the exposure risk via penetration into breathing zones in that row and numerous rows ahead and behind the index case. We completed over 65 releases of 180,000,000 fluorescent particles from the source, with 40+ Instantaneous Biological Analyzer and Collector sensors placed in passenger breathing zones for real-time measurement of simulated virus particle penetration.Results from both airframes showed a minimum reduction of 99.54% of 1 µm aerosols from the index source to the breathing zone of a typical passenger seated directly next to the source. An average 99.97 to 99.98% reduction was measured for the breathing zones tested in the 767 and 777, respectively. Contamination of surfaces from aerosol sources was minimal, and DNA-tagged 3 µm tracer aerosol collection techniques agreed with fluorescent methodologies.

Introduction As a result of the COVID-19 pandemic and highly contagious nature of SARS-CoV-2, emergency departments (EDs) have been forced to implement new measures and protocols to minimize the spread of the disease within their departments. The primary objective of this study was to determine if the implementation of a designated COVID-19 cohort area (hot zone) within a busy ED mitigated the dissemination of SARS-CoV-2 throughout the rest of the department. Methods In an ED of a tertiary academic medical center, with 64,000 annual visits, an eight room pod was designated for known COVID-19 or individuals with high suspicion for infection. There was a single entry and exit for donning and doffing personal protective equipment (PPE). Health care workers (HCW) changed gowns and gloves between patients, but maintained their N-95 mask and face shield, cleaning the shield with a germicidal wipe between patients. Staffing assignments designated nurses and technicians to remain in this area for 4 h, where physicians regularly moved between the hot zone and rest of the ED. Fifteen surface samples and four air samples were taken to evaluate SARS-CoV-2 contamination levels and the effectiveness of infection control practices. Samples were collected outside of patient rooms in 3 primary ED patient care areas, the reception area, the primary nurses station, inside the cohort area, and the PPE donning and doffing areas immediately adjacent. Samples were recovered and analyzed for the presence of the E gene of SARS-CoV-2 using RT-PCR. Results SARS-CoV-2 was not detected on any surface samples, including in and around the cohort area. All air samples outside the COVID-19 hot zone were negative for SARS-CoV-2, but air samples within the cohort area had a low level of viral contamination. Conclusion A designated COVID-19 cohort area resulted in no air or surface contamination outside of the hot zone, and only minimal air, but no surface contamination, within the hot zone.

Environmental chambers are a commonly used tool for studying the production and processing of aerosols in the atmosphere. Most are located indoors and most are filled with air having prescribed concentrations of a small number of reactive gas species. Here we describe portable chambers that are used outdoors and filled with mostly ambient air. Each all-Teflon® 1 m3 Captive Aerosol Growth and Evolution (CAGE) chamber has a cylindrical shape that rotates along its horizontal axis. A gas-permeable membrane allows exchange of gas-phase species between the chamber and surrounding ambient air with an exchange time constant of approximately 0.5 h. The membrane is non-permeable to particles, and those that are injected into or nucleate in the chamber are exposed to the ambient-mirroring environment until being sampled or lost to the walls. The chamber and surrounding enclosure are made of materials that are highly transmitting across the solar ultraviolet and visible wavelength spectrum. Steps taken in the design and operation of the chambers to maximize particle lifetime resulted in averages of 6.0, 8.2, and 3.9 h for ∼ 0.06, ∼ 0.3, and ∼ 2.5 µm diameter particles, respectively. Two of the newly developed CAGE chamber systems were characterized using data acquired during a 2-month field study in 2016 in a forested area north of Houston, TX, USA. Estimations of measured and unmeasured gas-phase species and of secondary aerosol production in the chambers were made using a zero-dimensional model that treats chemical reactions in the chamber and the continuous exchange of gases with the surrounding air. Concentrations of NO, NO2, NOy, O3, and several organic compounds measured in the chamber were found to be in close agreement with those calculated from the model, with all having near 1.0 best fit slopes and high r2 values. The growth rates of particles in the chambers were quantified by tracking the narrow modes that resulted from injection of monodisperse particles and from occasional new particle formation bursts. Size distributions in the two chambers were measured intermittently 24 h d−1. A bimodal diel particle growth rate pattern was observed, with maxima of about 6 nm h−1 in the late morning and early evening and minima of less than 1 nm h−1 shortly before sunrise and sunset. A pattern change was observed for hourly averaged growth rates between late summer and early fall.

As the world recovers from the lockdown imposed by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, returning to shared indoor spaces is considered a formidable risk. It is now clear that transmission of SARS-CoV-2 is driven by respiratory microdroplets expelled by infected persons, which can become suspended in the air. Several layering technologies are being explored to mitigate indoor transmission in the hopes of re-opening business, schools and transportation systems. Here we coupled the water adsorptive and photocatalytic capacity of novel Metal Organic Frameworks (MOFs) to demonstrate the capture and inactivation of SARS-CoV-2. Discussion is given on the methods of analysis and the differences between the photocatalytic activity of several MOFs, and the difference between MOF induced photocatalysis and ultra violet photolysis of SARS-CoV-2. Our results are intended to provide support to industry looking for alternative methods secure indoor spaces.

Study Objectives: Over 90,000 health care workers worldwide have been infected with SARS-CoV-2 In response to the COVID-19 pandemic, emergency departments (EDs) implemented new measures to minimize the spread of the disease within their patient care areas The primary objective of this study was to determine if SARS-CoV-2 viral particles were present on surfaces or in the air, in a designated COVID-19 cohort area, or ‘hot zone ’ Secondary analysis involved testing for viral particles in others areas of the ED outside of the ‘hot zone ’ Methods: This study took place in the ED of a tertiary academic medical center, with approximately 64,000 annual visits We designated a pod of 8 rooms for known COVID-19 infection or individuals with high suspicion for infection The area consisted of a single entry (Personal protective equipment donning area) and exit (PPE doffing area) Health workers would change gowns and gloves between patients, but maintain their N-95 mask and face shield, after cleaning with a germicidal wipe Fifteen surface samples and four air samples were taken in the ED to evaluate SARS-CoV-2 contamination levels and the effectiveness of infection control practices Samples were collected outside of patient rooms in 3 primary areas, the reception area, the primary nurses station, inside the cohort area, and the PPE donning and doffing areas immediately adjacent The 15 surface samples were collected using 3x3 sterile gauze pads pre-wetted with 3 mL of phosphate buffered saline (PBS), over an approximately 100 cm2 area by wiping in an “S” pattern in 2 directions Stationary air samples were collected using a Sartorius Airport MD8 air sampler operating at 30 liters per minute for 30 minutes onto an 80mm gelatin filter All samples were recovered in sterile PBS, had RNA extracted and were analyzed for the presence of SARS-CoV-2 by RT-PCR targeting the E gene of SARS-CoV-2 Results: SARS-CoV-2 was not detected on any surface samples collected in the ED All air samples outside the COVID-19 hot zone were also negative for SARS-CoV-2 The air samples from inside the cohort area had a low level of viral contamination, but no surface samples in or around the cohort area showed any indication of viral contamination These data suggest that despite having a large influx of COVID-19 patients on the day of sampling, the infection control practices were sufficient to either prevent or eliminate surface contamination The positive air sample from the cohort area suggests that respiratory protection with an N-95 respirator inside the cohort area, even outside of patient rooms is warranted to adequately protect health care providers Conclusion: A designated COVID-19 cohort area resulted in no air or surface contamination outside of the hot zone, and only minimal air, but no surface contamination, within the hot zone

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China in late 2019, and its resulting coronavirus disease, COVID-19, was declared a pandemic by the World Health Organization on March 11, 2020. The rapid global spread of COVID-19 represents perhaps the most significant public health emergency in a century. As the pandemic progressed, a continued paucity of evidence on routes of SARS-CoV-2 transmission has resulted in shifting infection prevention and control guidelines between classically-defined airborne and droplet precautions. During the initial isolation of 13 individuals with COVID-19 at the University of Nebraska Medical Center, we collected air and surface samples to examine viral shedding from isolated individuals. We detected viral contamination among all samples, supporting the use of airborne isolation precautions when caring for COVID-19 patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission causing coronavirus disease 2019 (COVID-19) may occur through multiple routes. We collected aerosol samples around six patients admitted into mixed acuity wards in April of 2020 to identify the risk of airborne SARS-CoV-2. Measurements were made to characterize the size distribution of aerosol particles, and size-fractionated, aerosol samples were collected to assess the presence of infectious virus in particles sizes of >4.1 µm, 1-4 µm, and 4.1 µm, 1-4 µm, and

Lack of evidence on SARS-CoV-2 transmission dynamics has led to shifting isolation guidelines between airborne and droplet isolation precautions. During the initial isolation of 13 individuals confirmed positive with COVID-19 infection, air and surface samples were collected in eleven isolation rooms to examine viral shedding from isolated individuals. While all individuals were confirmed positive for SARS-CoV-2, symptoms and viral shedding to the environment varied considerably. Many commonly used items, toilet facilities, and air samples had evidence of viral contamination, indicating that SARS-CoV-2 is shed to the environment as expired particles, during toileting, and through contact with fomites. Disease spread through both direct (droplet and person-to-person) as well as indirect contact (contaminated objects and airborne transmission) are indicated, supporting the use of airborne isolation precautions.One Sentence SummarySARS-CoV-2 is shed during respiration, toileting, and fomite contact, indicating that infection may occur in both direct and indirect contact.

Chemical reactions in aerosol particles can occur between the reactive components of the particle or between the particle and its surrounding media. The fate of atmospheric aerosols depends on the environment, the composition and the distribution of components within a particle. It could be very interesting to see how a liquid aerosol particle behaves in ambient air if the particle is composed of mixed chemicals. Do the chemical components remain homogeneously mixed within a particle or separate as the mixed liquid is aerosolized? How do the chemicals within a droplet separate and interact with the air? In this paper, a single microdroplet formed from an organic-organic mixture of diethyl phthalate (DEPh) and glycerol was investigated using laser-trapped position-resolved temporal Raman spectroscopy. For the first time, we were able to directly observe the gradient distributions of the two chemicals at different positions within such an airborne droplet, their time-resolved processes of liquid-liquid phase-separation, and changes of the physical microstructure and chemical micro-composition in the droplet. The results revealed that DEPh migrated to the surface and formed an outer layer and glycerol was more concentrated in the interior of the droplet, DEPh evaporated faster than glycerol, and both organic chemicals within the mixed droplet evaporated faster than either of them within their pure droplets. This technique also provides a new method for studying the fine structure and chemical reactions of different molecules taking place inside a particle and at the interface of a particle with the surrounding microenvironment.

We describe a new method for focusing and concentrating a stream of moving micron-sized aerosol particles in air. The focusing and concentrating process is carried out by the combined drag force and optical force that is generated by a double-layer co-axial nozzle and a focused doughnut-shaped hollow laser beam, respectively. This method should supply a new tool for aerosol science and related research.Copyright © 2018 American Association for Aerosol Research

We present an advanced optical-trapping method that is capable of trapping arbitrary shapes of transparent and absorbing particles in air. Two parabolic reflectors were used to reflect the inner and outer parts of a single hollow laser beam, respectively, to form two counter-propagating conical beams and bring them into a focal point for trapping. This novel design demonstrated high trapping efficiency and strong trapping robustness with a simple optical configuration. Instead of using expensive microscope objectives, the parabolic reflectors can not only achieved large numerical aperture (N.A.) focusing, but were also able to focus the beam far away from optical surfaces to minimize optics contamination. This design also offered a large free space for flexible integration with other measuring techniques, such as optical-trapping Raman spectroscopy, for on-line single particle characterization.

We present a comprehensive update on the studies of atmospheric aging processes for airborne bioaerosols under various laboratory-controlled conditions. We reviewed changes in physical, chemical, and biological properties of aerosolized biological organisms suspended in air under different simulated environmental parameters or open air factors (OAFs). These changes were scrutinized by measuring viability, inactivation, infectivity, DNA damage, qPCR signal, fluorescence spectral profile and intensity, or/and Raman spectral features. The OAFs considered here are the solar or ultra-violet (UV) radiation, heat or temperature, ozone (O3), free radicals, pollutants, relative humidity, and volatile organic compounds. Most times, especially in actual environmental conditions, far more than one of these factors were involved in the aging processes under various mixed conditions with different levels of individual factors and procedures applied. It is extremely challenging to quantitatively describe these changes of airborne bioaerosols under various combined influences of multiple OAFs. To date, there is not yet sufficient knowledge to enable us to quantitatively express relationships among viability, PCR signals, and spectral features for the atmospheric aging processes, except for some simple changes under particular conditions. Therefore, more comprehensive studies are strongly encouraged to be carried out to address those challenges in the field.

We demonstrate a method for simultaneously measuring the back-scattering patterns and images of single laser-trapped airborne aerosol particles. This arrangement allows us to observe how the back-scattering patterns change with particle size, shape, surface roughness, orientation, etc. The recoded scattering patterns cover the angular ranges of θ=167.7–180° (including at 180° exactly) and ϕ=0–360° in spherical coordinates. The patterns show that the width of the average speckle intensity islands or rings is inversely proportional to particle size and how the shape of these intensity rings or islands also depends on the surface roughness. For an irregularly shaped particle with substantial roughness, the back-scattering patterns are formed with speckle intensity islands, the size and orientations of these islands depend more on the overall particle size and orientation, but have less relevance to the fine alteration of the surface structure and shapes. The back-scattering intensity at 180° is very sensitive to the particle parameters. It can change from a maximum to a minimum with a change of 0.1% in particle size or refractive index. The method has potential use in characterizing airborne aerosol particles, and may be used to provide back-scattering information for LIDAR applications.

Bacterial aerosol have been observed and studied in the ambient environment since the mid nineteenth century. These studies have sought to provide a better understanding of the diversity, variability and factors that control the biological aerosol population. In this study, we show comparisons between diversity of culturable bacteria and fungi, using culture and clinical biochemical tests, and 16S rRNA diversity using Affymetrix PhyloChips. Comparing the culturable fraction and surveying the total 16S rRNA of each sample provides a comprehensive look at the bacterial population studied and allows comparison with previous studies. Thirty-six hour back-trajectories of the air parcels sampled, over the two day period beginning 4 November 2008, provide information on the sources of aerosol sampled on the campus of Johns Hopkins University Applied Physics Laboratory in Laurel, MD. This study indicates that back-trajectory modeling of air parcels may provide insights into the observed diversity of biological aerosol.

Background Spartalizumab (PDR001) is an anti-PD-1 monoclonal antibody that is been explored in different tumor types. Preliminary safety and efficacy results from Groups B (B) and C (C) of a phase Ib study investigating spartalizumab with platinum-based chemotherapy in PD-L1 unselected advanced NSCLC (NCT03064854) are reported here. Methods Treatment-naive, stage IIIB/IV NSCLC, EGFR/ALK/ROS-1(-) pts, PS 0-1, were assigned to B (non-squamous NSCLC) or C (squamous/non-squamous NSCLC) for 4 cycles (21 day/cycle) of spartalizumab (initial dose – 300 mg Q3W) + pemetrexed 500 mg/m2 + cisplatin 75 mg/m2 followed by maintenance spartalizumab + pemetrexed (in B), or 4 cycles of spartalizumab (initial dose – 300 mg Q3W) + paclitaxel 200 mg/m2 + carboplatin AUC 6 followed by maintenance with spartalizumab (in C). Primary endpoints are recommended dose for expansion (RDE) and ORR by investigator assessment. Results At data cutoff of 15 May 2019, 38 pts in B and 33 pts in C were treated; 14 pts (36.8%) in B and 4 pts (12.1%) in C are still receiving treatment. Primary reason for discontinuation was progressive disease: 13 of 38 pts (34.2%) in B and 25 of 33 pts (75.8%) in C. DLTs were grade 4 hyponatremia and grade 2 posterior reversible encephalopathy syndrome in B (2 pts) and grade 4 neutropenic colitis in C (1 pt). RDE of spartalizumab in combination with platinum-based chemotherapy for both groups was 300 mg Q3W. Most common AEs (≥50%, any grade) were nausea (73.7%) and neutropenia (50%) in B; neutropenia (57.6%) and anemia (54.5%) in C. ORR and complete response rate were 50% and 5.3% in B, and 51.5% and 3% in C. Median DOR (months; 95% CI) by investigator assessment was 13.8 (4.9, NE) in B and 8.2 (5.1, 15.4) in C. Median PFS (months; 95% CI) by investigator assessment was 10.4 (5.4, 15.0) in B and 6.3 (4.1, 10.1) in C. Responses were observed at different PD-L1 expression levels with higher rate in PD-L1 tumor proportion score (TPS) ≥ 50%. Assessment of additional immune biomarkers is ongoing. Conclusions RDE of spartalizumab in combination with platinum-based chemotherapy is 300 mg Q3W. Safety profile and preliminary clinical activity are consistent with prior experience with spartalizumab, other immune checkpoint inhibitors and chemotherapy treatments administered. Clinical trial identification NCT03064854. Editorial acknowledgement Shiva Krishna Rachamadugu, Novartis Healthcare Pvt Ltd, Hyderabad, India. Legal entity responsible for the study Novartis Pharmaceuticals Corporation. Funding Novartis Pharmaceuticals Corporation. Disclosure A. Santoro: Advisory / Consultancy: BMS, Servier, Gilead, Pfizer, Eisai, Bayer, Msd, Arqule; Speaker Bureau / Expert Testimony: Takeda, BMS, Roche, AbbVie, Amgen, Celgene, Servier, Gilead, Astrazeneca, Pfizer, Arqule, Lilly, Sandoz, Eisai, Novartis, Bayer, MSD. P. Garrido Lopez: Advisory / Consultancy: Roche, MSD, BMS, Boerhinger Ingelheim, Pfizer, AbbVie, Guardant Health, Novartis, Lilly, AstraZeneca, Janssen, Sysmex, Blueprint Medicines, Takeda; Speaker Bureau / Expert testimony: Roche, MSD, BMS, Pfizer, Novartis, Boerhinger Ingelheim, Rovi; Research grant / Funding (institution), For Clinical Trails: Roche, MSD, BMS, Takeda, Lilly, Pfizer, Novartis, PharmaMar, Celgene, Sanofi, GSK, Theradex Oncology, BluePrint Medicines; Research grant / Funding (institution), For Contracted Research: Guardant Health, Sysmex. D.S.W. Tan: Honoraria (self): Merck, Pfizer, Novartis, Boehringer Ingelheim, Roche, Takeda ; Advisory / Consultancy: Novartis, Bayer, Boehringer Ingelheim, Celgene, AstraZeneca, Eli-lily, Loxo; Research grant / Funding (self): Novartis, AstraZeneca, GlaxoSmithKline, Bayer, Pfizer ; Travel / Accommodation / Expenses: Merck, Pfizer, Novartis, Boehringer Ingelheim, Roche,Takeda . L. Paz-Ares: Honoraria (self): Roche, Novartis, Pfizer, Lilly, BMS, MSD, Merck, Boehringer Ing., AstraZeneca, Amgen, Sanofi, PharmaMar, Takeda; Leadership role: Genomica. F. Shepherd: Honoraria (self): Novartis, AstraZeneca, Roche, BMS, Merck, EMD Serono; Advisory / Consultancy: Novartis, AstraZeneca, Roche, BMS, Merck, EMD Serono; Shareholder / Stockholder / Stock options: AstraZeneca. A. Bearz: Advisory / Consultancy: Takeda; Boehringer Ingelheim, Roche , MSD, Novartis; Speaker Bureau / Expert testimony: Takeda; Boehringer Ingelheim, Roche , MSD; Pfizer; Research grant / Funding (institution): AstraZeneca. F. Barlesi: Honoraria (self): AstraZeneca, Bayer, Bristol-Myers Squibb, Boehringer–Ingelheim, Eli Lilly Oncology, F. Hoffmann–La Roche Ltd, Novartis, Merck, MSD, Pierre Fabre, Pfizer and Takeda; Research grant / Funding (institution): AbbVie, ACEA, Amgen, AstraZeneca, Bayer, Bristol-Myers Squibb, Boehringer–Ingelheim, Eisai, Eli Lilly Oncology, F. Hoffmann–La Roche Ltd, Genentech, Ipsen, Ignyta, Innate Pharma, Loxo, Novartis, MedImmune, Merck, MSD, Pierre Fabre, Pfizer, Sanofi-Aventis; Non-remunerated activity/ies: Principal Investigator for AstraZeneca, BMS, Merck, Pierre Fabre and F. Hoffmann-La Roche, Ltd, sponsored trials (or ISR). J.F. Vansteenkiste: Honoraria (self), Advisory / Consultancy: AstraZeneca, Boehringer Ingelheim, Eli Lilly, MSD, Roche, Apotex; Research grant / Funding (institution): MSD. T.M. Kim: Research grant / Funding (institution): Alpha Biopharma, AstraZeneca/MedImmune, Hanmi, Janssen, Merus, Mirati Therapeutics, MSD, Novartis, ONO Pharmaceutical, Pfizer, Roche/Genentech, Takeda, TP Therapeutics, Xcovery, and Yuhan ; Research grant / Funding (self): AstraZeneca ; Non-remunerated activity/ies, Advisory / Consultancy: AstraZeneca, Novartis, Sanofi, and Bayer . T.R. Overbeck: Advisory / Consultancy, Consulting fees: AstraZeneca, BMS, Boehringer Ingelheim, Eli Lilly, Medac, MSD, Novartis, Roche/Genentech; Research grant / Funding (institution), sponsored research agreements: AstraZeneca, Eli Lilly, Roche/Genentech, Sanofi-Aventis; Travel / Accommodation / Expenses, Travel Support: AstraZeneca, Boehringer Ingelheim, Eli Lilly and Roche/Genentech. I.I. Rybkin: Research grant / Funding (institution): Merck, AbbVie, ARMO Biosciences, Beyond Spring Pharmaceutical, Bristol-Myers Squibb, Novartis, Mirati Therapeutical Inc., Nilogen, Inc., Pfizer, Polaris Group, Syndax Inc., Xcovery Inc., BerGenBio AS, Incyte Corporation, AstraZeneca, Amgen; Advisory / Consultancy: AstraZeneca. E. Felip: Advisory / Consultancy: AbbVie, AstraZeneca, Blue Print Medicines, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Guardant Helath, Janssen, Medscape, Merck Kgaa, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Takeda, Touchtime; Speaker Bureau / Expert Testimony: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lilly, Merck Kgaa, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Takeda; Research Grant / Funding (Self): Fundacion Merck Salud Grant For Oncology Innovation Emd Serono. W. Zhou: Full / Part-time employment: Novartis. L. Santarpia: Full / Part-time employment: Novartis. S. Eddy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Novartis. All other authors have declared no conflicts of interest.

Background: The presence of tumor-infiltrating lymphocytes (TILs) is a prognostic factor in triple-negative breast cancer (TNBC). In particular, cytotoxic CD8+ cells are associated with favorable outcome in TNBC. Recently, the integrin CD103 have been suggested as a potential prognostic marker in a small cohort of triple-negative/basal-like breast cancer (Wang et al, Clin Cancer Res 2016). In this study, we aimed to evaluate the functional status and clinical relevance of CD8+ and CD103+ TILs in TNBC. Methods: A large collection of formalin-fixed, paraffin-embedded tissues was retrospectively collected from 210 patients with primary invasive ductal TNBC. The presence of CD8, CD103 and the checkpoint receptor PD-1 was assessed by immunohistochemistry. Whole tumor slides were independently assessed by two pathologists blinded for patient characteristics and outcome. Cases where ≥5% of TILs expressed CD103 or PD-1 were considered positive. Statistical analyses were performed using Spearman's correlation, Kaplan-Meier and Cox regression analyses. Results: We found that CD103+ cells mostly co-expressed the CD8 marker, and were preferentially distributed within tumor epithelium. No consistent correlation was found between the presence of CD103+ lymphocytes and the expression of its ligand E-cadherin by TNBC cells (rs=0.365). CD8+ lymphocytes were consistently associated with better relapse-free survival (RFS) and overall survival (OS) in both univariate (HR=0.61; P=1.06E-02 for RFS; HR=0.59; P=1.93E-02 for OS) and multivariate analysis (HR=0.65; P=2.45E-02 for RFS; HR=0.63; P=3.96E-02 for OS). The presence of CD103+ lymphocytes significantly correlated with prolonged RFS and OS in univariate analysis only (HR=0.82; P=4.12E-02 for RFS; HR=0.85; P=4.93E-02 for OS), and a trend for longer RFS was also observed in univariate analysis for PD-1 (HR=0.71; P=5.22E-02). Interestingly, a subset of TNBC showed co-expression of CD103+/PD-1+ in lymphocytes localized to the intraepithelial areas of the tumor. Conclusions: The expression of CD103 on CD8+ T cells in direct contact with cancer cells may identify a subpopulation of cells with potent cytolytic activity. The interaction between CD103+ cytotoxic lymphocytes and cancer cells is mediated by mechanisms other than the binding to E-cadherin. Even though CD103 has a role in mediating an effective anti-tumor immune response, its presence alone may not be sufficient to impact the outcome of TNBC patients. Immunomodulatory therapies may be useful to boost the anti-tumor activity of potentially quiescent CD103+/PD-1+ cells in a subgroup of TNBC. Citation Format: Bottai G, Loi S, Sotiriou C, Roncalli M, Pusztai L, Reis-Filho JS, Santarpia L. CD103+/PD-1+ T-cells identify a subset of triple-negative breast cancer eligible for targeted checkpoint inhibition [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-04-16.

It could be very useful to detect and monitor the molecules and molecular reactions located at different positions within a microsized particle as they respond to various micro-local environments. In this Letter, a particular optical trap using two focusing counterpropagating hollow beams was able to stably trap both absorbing and nonabsorbing particles in air for lengthy observation. A technique that can measure the Raman spectra from different submicrometer positions of a laser-trapped single airborne particle was developed. Spontaneous and stimulated Raman scattering spectra originating from different positions of a diethyl phthalate droplet were recorded, and the strong Raman scattering signals are the result of cavity-enhanced effects and the localized strong light illumination.

Detection and characterization of the presence of chemical agent aerosols in various complex atmospheric environments is an essential defense mission. Raman spectroscopy has the ability to identify chemical molecules, but there are limited numbers of photons detectable from single airborne aerosol particles as they are flowing through a detection system. In this paper, we report on a single-particle Raman spectrometer system that can measure strong spontaneous, stimulated, and resonance Raman spectral peaks from a single laser-trapped chemical aerosol particle, such as a droplet of the VX nerve agent chemical simulant diethyl phthalate. Using this system, time-resolved Raman spectra and elastic scattered intensities were recorded to monitor the chemical properties and size variation of the trapped particle. Such a system supplies a new approach for the detection and characterization of single airborne chemical aerosol particles.

The effects of ozone and relative humidity (RH) at common atmospheric levels on the properties of single octapeptide bioaerosol particles were studied using an improved rotating reaction chamber, an aerosol generator, an ultraviolet aerodynamic particle sizer (UVAPS), an improved single particle fluorescence spectrometer (SPFS), and equipments to generate, monitor and control the ozone and RH. Aerosol particles (mean diameter ~2 μm) were generated from a slurry of octapeptide in phosphate buffered saline, injected into the rotating chamber, and kept airborne for hours. Bioaerosols were sampled from the chamber hourly for the measurements of particle-size distribution, concentration, total fluorescence excited at 355-nm, and single particle fluorescence spectra excited at 266-nm and 351-nm under different controlled RH (20%, 50%, or 80%) and ozone concentration (0 or 150 ppb). The results show that: (1) Particle size, concentration, and the 263-nm-excited fluorescence intensity decrease at different rates under different combinations of the RH and ozone concentrations used. (2) The 263-nm-excited UV fluorescence (280–400 nm) decreased more rapidly than the 263-nm-excited visible fluorescence (400–560 nm), and decreased most rapidly when ozone is present and RH is high. (3) The UV fluorescence peak near 340 nm slightly shifts to the shorter wavelength (blue-shift), consistent with a more rapid oxidation of tryptophan than tyrosine. (4) The 351/355-nm-excited fluorescence (430–580 nm/380–700 nm) increases when ozone is present, especially when the RH is high. (5) The 351/355-nm-excited fluorescence increase that occurs as the tryptophan emission in the UV decreases, and the observation that these changes occur more rapidly at higher RH with the present of ozone, are consistent with the oxidation of tryptophan by ozone and the conversion of the resulting ozonides to N-formyl kynurenine and kynurenine.

Time-resolved characterization of biological aerosol is important both for understanding environmental processes that affect biological aerosols and for determining realistic test conditions for the evaluation of bioaerosol detection systems. Very little work has been done to develop an understanding of the temporal fluctuations in bioaerosol concentration. During an experiment from 1–10 November 2008 ambient biological aerosol and meteorological data were collected. A FLIR/ICx/S3I Instantaneous Bioaerosol Analysis and Collection sensor was used to count both the biological and nonbiological aerosol in two size bins. The data indicate that the ambient relative humidity affects the optically observable concentration of biological aerosol with higher relative humidity generally associated with higher biological aerosol concentrations. The short timescale over which these correlations exist implies an aerosol process, rather than a change in aerosol source. © 2013 American Association for Aerosol Research

We demonstrate a method for measuring elastic back-scattering patterns from single laser trapped micron-sized particles, spanning the scattering angle range of θ=167.7°–180° and φ=0°–360° in spherical coordinates. We calibrated the apparatus by capturing light-scattering patterns of 10 μm diameter borosilicate glass microspheres and comparing their scattered intensities with Lorenz–Mie theory. Back-scattering patterns are also presented from a single trapped Johnson grass spore, two attached Johnson grass spores, and a cluster of Johnson grass spores. The method has potential use in characterizing airborne aerosol particles, and may be used to provide back-scattering data for lidar applications.

Tryptophan is a fluorescent amino acid common in proteins. Its absorption is largest for wavelengths λ ≲ 290 nm and its fluorescence emissions peak around 300-350 nm, depending upon the local environment. Here we report the observation of red fluorescence near 600 nm emerging from 488-nm continuous-wave (CW) laser photoexcitation of dry tryptophan (Trp) particles. With an excitation intensity below 0.5 kW/cm2, dry Trp particles yield distinctive Raman scattering peaks in the presence of relatively weak and spectrally broad emissions with λ ∼500-700 nm, allowing estimation of particle temperature at low excitation intensities. When the photoexcitation intensity is increased to 1 kW/cm2 or more for a few minutes, fluorescence intensity dramatically increases by more than two orders of magnitude. The fluorescence continues to increase in intensity and gradually shift to the red when photoexcitation intensity and the duration of exposure are increased. The resulting products absorb at visible wavelengths and generate red fluorescence with λ ∼ 650-800 nm with 633-nm CW laser excitation. We attribute the emergence of orange and red fluorescence in the Trp products to a photochemical transformation that is instigated by weak optical transitions to triplet states in Trp with 488-nm excitation and which may be expedited by a photothermal effect.

During June and July of 2004, airborne measurements of size-resolved aerosol properties were made over the coastal Pacific near Marina, California. Tandem differential mobility analysis was used to determine the hygroscopic properties of these aerosols and, subsequently, to examine the change in soluble mass after the aerosol had been cloud-processed. Three of the eight cases analyzed during the field campaign exhibited increased soluble mass attributable to cloud-processing. The calculated change in soluble mass after cloud-processing, derived from measurements made below and above cloud, ranged from 1.08 ϒ g m−3 to 1.40 ϒ g m−3. These values are in agreement with those determined using data collected during previous field studies in the same region. Aerosol size distributions measured throughout the study with a Passive Cavity Aerosol Spectrometer Probe were averaged to create a single representative distribution, which was used to examine the impact of the addition of sulfate to a typical aerosol measured during this project. Mass light-scattering efficiencies were calculated for both the initial and cloud-processed size distributions using Mie-Lorenz theory. These calculations show that the increase in mass light-scattering efficiency following passage through a single non-precipitating cloud to be 14%, which is in agreement with findings of previous studies in the same region. This new technique produces results that are consistent with existing methods for measuring in-cloud sulfate production and has the advantage of intrinsic consistency with the hygroscopicity and CCN activity of the aerosol.

There is a growing need to evaluate bioaerosol sensors under relevant operational conditions. New methods are needed that can mimic the temporal fluctuations of ambient aerosol backgrounds and present biological aerosol challenges in a way that simulates a plausible biological agent attack. The Dynamic Concentration Aerosol Generator was developed to address this need. The authors developed a series of aerosol challenges consisting of Bacillus thuringiensis kurstaki (Btk) spores in the presence of background aerosols using a newly developed ramp testing method. Using ramping style tests, 5-min Btk releases were overlaid on top of a background aerosol that fluctuated at varying rates. Background aerosol compositions for different tests were designed to simulate the types of aerosol in the ambient environment. Background aerosol concentration was varied between 7.0 × 103 and 1.5 × 104 particles per liter of air (ppL). Aerosol number concentrations of Btk for the challenges were approximately 2.5 × 103 ppL a...