Dust Under the Radar: Rethinking How to Evaluate the Impacts of Dust Events on Air Quality in the United States.

Dust is an important and complex constituent of the atmospheric system, having significant impacts on the environment, climate, air quality, and human health. Although dust events are common across many regions of the United States, their impacts are not often prioritized in air quality mitigation strategies. We argue that there are at least three factors that result in underestimation of the social and environmental impact of dust events, making them receive less attention. These include (a) sparse monitoring stations with irregular spatial distribution in dust-influenced regions, (b) inconsistency with dust sampling methods, and (c) sampling frequency and schedules, which can lead to missed dust events or underestimation of dust particle concentrations. Without addressing these three factors, it is challenging to characterize and understand the full air quality impacts of dust events in the United States. This paper highlights the need for additional monitoring to measure these events so that we can more fully evaluate and understand their impacts, as they are predicted to increase with climate change.

Computational Fluid Dynamics Simulations to Assess Spatial Variability and Optimal Ventilation Scenarios for Biological Laboratory Exposures.

Introduction: A significant amount of uncertainty exists regarding potential human exposure to laboratory biomaterials and organisms in Biosafety Level 2 (BSL-2) research laboratories. Computational fluid dynamics (CFD) modeling is proposed as a way to better understand potential impacts of different combinations of biomaterials, laboratory manipulations, and exposure routes on risks to laboratory workers. Methods: In this study, we use CFD models to simulate airborne concentrations of contaminants in an actual BSL-2 laboratory under different configurations. Results: Results show that ventilation configuration, sampling location, and contaminant source location can significantly impact airborne concentrations and exposures. Depending on the source location and airflow patterns, the transient and time-integrated concentrations varied by several orders of magnitude. Contaminant plumes from sources located near a return vent (or exhaust like a fume hood or ventilated biosafety cabinet) are likely to be more contained than sources that are further from the exhaust. Having a direct flow between the source and the exhaust (through-flow condition) may reduce potential exposures to individuals outside the air flow path. Conclusion: Designing a BSL-2 room with ventilation and airflow patterns that maximize through-flow conditions to the return/exhaust vents and minimize dispersion and mixing throughout the room is, therefore, recommended. CFD simulations can also be used to assist in characterizing the impacts of supply and return vent locations, room layout, and source locations on spatial and temporal contaminant concentrations. In addition, proper placement of particle sensors can also be informed by CFD simulations to provide additional characterization and monitoring of potential exposures in BSL-2 facilities.

Modeling airborne pathogen transport and transmission risks of SARS-CoV-2.

An integrated modeling approach has been developed to better understand the relative impacts of different expiratory and environmental factors on airborne pathogen transport and transmission, motivated by the recent COVID-19 pandemic. Computational fluid dynamics (CFD) modeling was used to simulate spatial-temporal aerosol concentrations and quantified risks of exposure as a function of separation distance, exposure duration, environmental conditions (e.g., airflow/ventilation), and face coverings. The CFD results were combined with infectivity models to determine probability of infection, which is a function of the spatial-temporal aerosol concentrations, viral load, infectivity rate, viral viability, lung-deposition probability, and inhalation rate. Uncertainty distributions were determined for these parameters from the literature. Probabilistic analyses were performed to determine cumulative distributions of infection probabilities and to determine the most important parameters impacting transmission. This modeling approach has relevance to both pathogen and pollutant dispersion from expelled aerosol plumes.

Techno-Economic Optimization of CSP Plants with Free-Falling Particle Receivers.

Particle receivers are one of the candidates for the next generation of CSP plants, whose goal is to reduce the levelized cost of electricity (LCOE) to 0.05 $/kWh. This paper presents a techno-economic analysis to study if a CSP system with free-falling particle receiver can achieve this goal. The plant analyzed integrates two ground-based bins to store the excess energy and a supercritical CO2 cycle to generate electricity. The model used for the analysis presents several upgrades to previous particle systems models in order to increase its fidelity, accuracy, and representativeness of an actual system. The main upgrades are the addition of off-design conditions during the annual simulations in all the components and an improved receiver model validated against CFD simulations. The size of the main components is optimized to obtain the system configuration with minimum LCOE. The results show that particle CSP systems can reduce the LCOE to 0.056 $/kWh if the configuration is composed of 1.61 × 106 m2 of heliostats, a 250 m high tower with a 537 m2 falling particle curtain, and 16 h thermal energy storage.

Does adjuvant radiotherapy benefit patients with diffuse-type gastric cancer? Results from the Surveillance, Epidemiology, and End Results database.

BACKGROUND: Diffuse-type gastric cancer is observed in approximately one-third of gastric cancers, yet the optimal treatment remains controversial. In the recently published Intergroup 0116 trial, a subgroup analysis demonstrated a lack of a long-term survival benefit for adjuvant chemoradiation therapy among patients with diffuse-type gastric cancer. METHODS: The Surveillance, Epidemiology, and End Results registry database was queried for patients who were newly diagnosed with diffuse-type gastric cancer between 2002 and 2005 and underwent surgical resection with or without adjuvant radiotherapy (RT). Overall survival (OS) was analyzed by the Kaplan-Meier method. Cox proportional hazards models were used to investigate the association between adjuvant RT and OS, with and without adjusting for other factors. In addition, propensity score methods were used to control for the possible effects of measured confounders. RESULTS: A total of 1889 cases of surgically resected diffuse-type gastric cancer were included in the analysis; of these cases, 782 patients received adjuvant RT and 1107 did not receive RT. The median survival time was 30 months in the group treated with adjuvant RT versus 18 months in the group that did not receive RT with matched propensity scores (P<.001). The Cox model confirmed the improvement in OS in patients who received adjuvant RT (hazard ratio, 0.75; 95% confidence interval, 0.65-0.82 [P<.001]). CONCLUSIONS: The current population-based observational study suggested a potential survival benefit for adjuvant RT among patients with diffuse-type gastric cancer. The standard treatment will likely remain controversial until evidence becomes available from phase 3 randomized trials exclusively for patients with diffuse-type gastric cancer.

Patterns of care for locally advanced vulvar cancer.

OBJECTIVE: Patients with locally advanced vulvar carcinoma can be treated with primary surgery or neoadjuvant chemoradiation. Neoadjuvant treatment appears to be associated with decreased morbidity and acceptable long-term outcomes. We examined the patterns of care for women with locally advanced vulvar cancer. STUDY DESIGN: Data from the Surveillance, Epidemiology, and End Results (SEER) database was used to examine women with stage III-IVA vulvar cancer treated from 1988 to 2008. Primary therapy was classified as surgery or radiation. Multivariable logistic regression models were developed to examine the use of primary radiotherapy. RESULTS: We identified a total of 2292 women including 1757 who underwent primary surgery (76.7%) and 535 treated with primary radiation (23.3%). The use of primary radiation increased with time from 18.0% in 1988 to 30.1% in 2008. In a multivariable model, older women (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.03-1.72), black women (OR, 1.59; 95% CI, 1.14-2.23), and patients with stage IVA tumors (OR, 2.23; 95% CI, 1.78-2.81) were more likely to receive primary radiation. Among women treated with primary radiotherapy, only 17.8% ultimately underwent surgical resection. CONCLUSION: The use of primary radiation for locally advanced vulvar cancer is limited but has increased over time. Multiple patient and tumor factors influence use. The majority of patients with stage III-IVA vulvar cancer treated with primary radiation therapy did not undergo surgical resection.

Patterns of care and treatment outcomes for elderly women with cervical cancer.

BACKGROUND: Cervical cancer is common in the elderly. The authors examined the patterns of care, treatment, and outcomes of elderly women with cervical cancer. METHODS: Women with cervical cancer diagnosed between 1988 and 2005 and registered in the Surveillance, Epidemiology, and End Results database were analyzed. Patients were stratified by age: <50, 50 to 59, 60 to 69, 70 to 79, and ≥80 years. Multivariate logistic regression models were constructed to examine treatment; cancer-specific survival was examined using Cox proportional hazards models. RESULTS: A total of 28,902 women were identified, including 2543 women 70 to 79 years old and 1364 ≥80 years. For women with early stage (IB1-IIA) tumors, primary surgery was performed in 82.0% of women <50 years old compared with 54.5% of those 70 to 79 years old and 33.2% of those ≥80 years old (P < .0001). For women treated surgically, lymphadenectomy was performed in 66.8% of women <50 years old versus 9.1% of patients ≥80 years old (P < .0001). Compared with patients <50 years old, those >80 years old were less likely to undergo radical hysterectomy (odds ratio [OR], 0.10; 95% confidence interval [CI], 0.07-0.14) and lymphadenectomy (OR, 0.11; 95% CI, 0.08-0.16) and to receive adjuvant radiation therapy (OR, 0.06; 95% CI, 0.01-0.35). Among women with stage IIB-IVA disease, use of brachytherapy declined with age (P < .0001). For women with stage IB1-IIA tumors, the hazard ratio for death from cancer was 1.35 (95% CI, 1.16-1.58) for women 70 to 79 years old and 2.08 (95% CI, 1.72-2.48) for those ≥80 years old compared with younger women. CONCLUSIONS: Elderly women with cervical cancer are less likely to undergo surgery, receive adjuvant radiation, and receive brachytherapy. After adjusting for treatment disparities, cancer-specific mortality is higher in older women.

Lymphadenectomy influences the utilization of adjuvant radiation treatment for endometrial cancer.

OBJECTIVE: We analyzed the effect of lymphadenectomy on the use of adjuvant radiation treatment for women with stage I-II endometrial cancer. STUDY DESIGN: Women with stage I-II endometrioid adenocarcinomas treated between 1988 and 2006 and recorded in the Surveillance, Epidemiology, and End Results database were identified. The influence of lymphadenectomy (LND) on receipt of external beam radiation and brachytherapy stratified was examined. RESULTS: We identified 58,776 women including 26,043 who underwent LND (44.3%). Among women younger than 60 years of age with stage IA (grades 1, 2, and 3) tumors, LND had no impact on the use of radiation. Patients with stage IB (grade 2 or 3) and stage IC (grade 1 or 2) tumors who underwent lymph node dissection were less likely to undergo external beam radiation and more likely to receive vaginal brachytherapy (P < .05 for all). Furthermore, the extent of lymphadenectomy influenced the receipt of radiation. CONCLUSION: Women who undergo lymphadenectomy are less likely to receive whole pelvic radiotherapy.

Down-regulation of microRNA 106b is involved in p21-mediated cell cycle arrest in response to radiation in prostate cancer cells.

BACKGROUND: microRNAs (miRNAs) are endogenous short non-coding RNAs, and play a pivotal role in regulating of a variety of cellular processes, including proliferation and apoptosis, both of which are cellular responses to radiation treatment. The purpose of this study is to identify candidate miRNAs whose levels are altered in response to radiation in prostate cancer cells and to investigate the molecular pathway of such miRNAs in the regulation of radiation-induced cellular response. METHODS: Using a miRNA microarray assay, we screened 132 cancerous miRNAs in LNCaP cells in response to radiation treatment. The function of one candidate miRNA was investigated for checkpoint protein expression, cell cycle arrest, cell proliferation, and cell survival in cells transfected with precursor or antisense miRNA. RESULTS: In response to radiation, multiple miRNAs, including mi-106b, showed altered expression. Cells transfected with precursor miR-106b were able to suppress radiation-induced p21 activation. Functionally, exogenous addition of precursor miR-106b overrode the G2/M arrest in response to radiation and resulted in a transient diminishment of radiation-induced growth inhibition. CONCLUSION: We have shown a novel role of miR-106b, in the setting of radiation treatment, in regulating the p21-activated cell cycle arrest. Our finding that miR-106b is able to override radiation-induced cell cycle arrest and cell growth inhibition points to a potential therapeutic target in certain prostate cancer cells whose radiation resistance is likely due to consistently elevated level of miR-106b.

Systematic analysis of micromixers to minimize biofouling on reverse osmosis membranes.

Micromixers, UV-curable epoxy traces printed on the surface of a reverse osmosis membrane, were tested on a cross-flow system to determine their success at reducing biofouling. Biofouling was quantified by measuring the rate of permeate flux decline and the median bacteria concentration on the surface of the membrane (as determined by fluorescence intensity counts due to nucleic acid stains as measured by hyperspectral imaging). The micromixers do not appear to significantly increase the pressure needed to maintain the same initial permeate flux and salt rejection. Chevrons helped prevent biofouling of the membranes in comparison with blank membranes. The chevron design controlled where the bacteria adhered to the membrane surface. However, blank membranes with spacers had a lower rate of permeate flux decline than the membranes with chevrons despite having greater bacteria concentrations on their surfaces. With better optimization of the micromixer design, the micromixers could be used to control where the bacteria will adhere to the surface and create a more biofouling resistant membrane that will help to drive down the cost of water treatment.

Multi-institutional trial of accelerated hypofractionated intensity-modulated radiation therapy for early-stage oropharyngeal cancer (RTOG 00-22).

PURPOSE: To assess the results of a multi-institutional study of intensity-modulated radiation therapy (IMRT) for early oropharyngeal cancer. PATIENTS AND METHODS: Patients with oropharyngeal carcinoma Stage T1-2, N0-1, M0 requiring treatment of the bilateral neck were eligible. Chemotherapy was not permitted. Prescribed planning target volumes (PTVs) doses to primary tumor and involved nodes was 66 Gy at 2.2 Gy/fraction over 6 weeks. Subclinical PTVs received simultaneously 54-60 Gy at 1.8-2.0 Gy/fraction. Participating institutions were preapproved for IMRT, and quality assurance review was performed by the Image-Guided Therapy Center. RESULTS: 69 patients were accrued from 14 institutions. At median follow-up for surviving patients (2.8 years), the 2-year estimated local-regional failure (LRF) rate was 9%. 2/4 patients (50%) with major underdose deviations had LRF compared with 3/49 (6%) without such deviations (p = 0.04). All cases of LRF, metastasis, or second primary cancer occurred among patients who were current/former smokers, and none among patients who never smoked. Maximal late toxicities Grade >or=2 were skin 12%, mucosa 24%, salivary 67%, esophagus 19%, osteoradionecrosis 6%. Longer follow-up revealed reduced late toxicity in all categories. Xerostomia Grade >or=2 was observed in 55% of patients at 6 months but reduced to 25% and 16% at 12 and 24 months, respectively. In contrast, salivary output did not recover over time. CONCLUSIONS: Moderately accelerated hypofractionatd IMRT without chemotherapy for early oropharyngeal cancer is feasible, achieving high tumor control rates and reduced salivary toxicity compared with similar patients in previous Radiation Therapy Oncology Group studies. Major target underdose deviations were associated with higher LRF rate.

Development and validation of a concise emotional inventory.

This study investigated the initial development and validation of a concise emotional inventory. The scale was developed as a very expedient device that can be used with young adults in order to access a person's emotional state across a wide variety of defined life content areas. The version of the scale used in this study was specifically developed and validated for use with college-aged students modeling experimental procedures developed by Nowicki (2000). Studies dealing with emotional differences among young student music populations were not found in the literature. Effective use of this scale for music therapists requires some form of "validation" with college-aged students in order to investigate how music therapists may use such a scale to assist their assessment of a person within this particular population. It is noted, however that these comparisons may inform potential use of this scale, but should not provide "normative" data for music life assessments. It must be remembered this inventory is designed only to give information specific to each person. Therefore, group comparisons are made solely to demonstrate reliability across various geographical areas and college populations. Thus, "reliability" measures presented are intended only to demonstrate that the inventory can be administered easily and used to identify potential areas, issues, situations or persons who are capable of eliciting negative or positive related ideations.

Cyclin D1 guanine/adenine 870 polymorphism with altered protein expression is associated with genomic instability and aggressive clinical biology of esophageal adenocarcinoma.

PURPOSE: Altered cyclin D1 (CD1), a cell cycle regulator, may play an important role in imparting aggressive nature to esophageal adenocarcinoma (EAC). CD1 gene single nucleotide polymorphism G/A870 results in two alternatively spliced transcripts, CD1a and CD1b. CD1b, preferentially encoded by the A870 allele, is putatively oncogenic. We hypothesized that CD1 A870 allele would be associated with higher CD1 protein expression, and increased genomic instability during EAC evolution, leading to more aggressive phenotype. PATIENTS AND METHODS: One hundred twenty-four archival specimens of EAC, and 39 associated Barrett's esophagus (BE) specimens were examined for CD1 genotype, CD1 protein expression, and chromosome 9 polysomy (representing genomic instability). We correlated CD1 genotypes with CD1 protein expression, genomic instability, age at diagnosis of EAC, and overall survival (OS). RESULTS: The A870 allele was associated with higher levels of CD1 protein expression in EAC (P = .032); in BE (P = .01) where it was associated with concomitant increased chromosome 9 polysomy (P = .002); and with a younger age at diagnosis (P < .001) and poor OS (P = .0003) of EAC patients. CONCLUSION: Our data suggest that CD1 A870 background may be imparting aggressive phenotype to EAC. It provides a molecular basis to explain the clinical biology associated with CD1 polymorphism whereas aberrant nuclear accumulation of CD1 protein enhances the acquisition of genomic instability (ie, clonal diversity), thus leading to early age of EAC diagnosis and poor OS. CD1 genotyping with other biomarkers may help create a biomarker-based prognostic model for EAC and CD1 may also serve as a therapeutic target.

Modeling Carbon-Black/Polymer Composite Sensors.

Conductive polymer composite sensors have shown great potential in identifying gaseous analytes. To more thoroughly understand the physical and chemical mechanisms of this type of sensor, a mathematical model was developed by combining two sub-models: a conductivity model and a thermodynamic model, which gives a relationship between the vapor concentration of analyte(s) and the change of the sensor signals. In this work, 64 chemiresistors representing eight different carbon concentrations (8-60 vol% carbon) were constructed by depositing thin films of a carbon-black/polyisobutylene composite onto concentric spiral platinum electrodes on a silicon chip. The responses of the sensors were measured in dry air and at various vapor pressures of toluene and trichloroethylene. Three parameters in the conductivity model were determined by fitting the experimental data. It was shown that by applying this model, the sensor responses can be adequately predicted for given vapor pressures; furthermore the analyte vapor concentrations can be estimated based on the sensor responses. This model will guide the improvement of the design and fabrication of conductive polymer composite sensors for detecting and identifying mixtures of organic vapors.

Pretherapy nuclear factor-kappaB status, chemoradiation resistance, and metastatic progression in esophageal carcinoma.

BACKGROUND: Transcriptional factor nuclear factor-kappaB (NF-kappaB) seems to be associated with aggressive clinical biology (chemoradiation resistance and metastatic progression) of esophageal cancer. We hypothesized that activated NF-kappaB would define clinical biology irrespective of the type of chemotherapy or sequence administered. METHODS: Pretherapy and/or posttherapy cancer specimens were examined for activated NF-kappaB and correlated with pathologic response to chemoradiation, metastatic potential, overall survival, disease-free survival, and type of chemotherapy or sequence used. FINDINGS: Eighty patients undergoing chemotherapy and concurrent radiation were studied. Activated NF-kappaB prior to any therapy was associated with the lack of complete pathologic response (pathCR, P = 0.006). Forty-five (78%) of 58 patients achieving

Intrapelvic migration of the trial femoral head during total hip arthroplasty: is retrieval necessary? A report of four cases.

When testing intra-operative range of motion during a total hip arthroplasty procedure with trial components, there is potential for the femoral head to dissociate from the trial neck. We report the dissociation of the trial femoral head with migration of the head into the pelvis while checking for anterior stability of the total hip arthroplasty construct. Options for retrieval of the head are outlined.

Effects of external beam radiation in the rat tibial nerve after crush, transection and repair, or nerve isograft paradigms.

INTRODUCTION: In head and neck surgery, radiation therapy is often administered to an injured nerve. Previous studies have examined the effects of either preoperative or postoperative radiation on nerve regeneration in rodents. In these studies, histomorphometric analysis was performed up to 8 month postoperatively. Given the exceptional neuroregenerative capacity of rodents, significant differences in nerve regeneration may go undetected if nerves are evaluated at such distant postoperative time points. This study is designed with a more appropriate model and investigates the effects of radiation after three common nerve injury paradigms. METHODS: Sixty-four Lewis rates were randomized to 8 groups corresponding to uninjured, tibial nerve crush, transection and repair, or reconstruction with isografts. Half of the animals in each of these paradigms (n = 8 per group) were treated with 10 Gy of external beam radiation to the site of nerve injury at 7 days postoperatively. On postoperative day 28, functional recovery and histomorphometric assessment was performed. RESULTS: For a given paradigm of nerve injury, no significant differences in nerve fiber number, neural density, neural debris, or fiber width were noted between the control and radiated groups, and radiation did not affect functional recovery. CONCLUSION: Radiation had no discernible effect on nerve regeneration or functional recovery in the rodent nerve injury models studied. All assessments were made at time points suitable for detecting differences in nerve regeneration between groups. These findings suggest that administration of radiation to fields containing injured peripheral nerve is unlikely to adversely affect functional outcomes.

Computed tomography in suppurative ear disease: does it influence management?

The value of high resolution computerized tomography (CT) prior to routine mastoid surgery for cholesteatoma remains controversial. Doubts about sensitivity and specificity, in detecting the extent of underlying pathology and in predicting asymptomatic complications, prevent widespread adoption. This retrospective study looks at the influence of pre-operative scanning on the surgical management of chronic suppurative otitis media over an 18-month period. The radiological findings determined the choice of surgical approach, but contributed less to the decision to operate and the prediction of potential hazards. CT is of most value when the otologist can be flexible in surgical technique, tailoring it to imaging findings.

Performance assessment model development and analysis of radionuclide transport in the unsaturated zone, Yucca Mountain, Nevada.

This paper describes the development and use of a particle-tracking model to perform radionuclide-transport simulations in the unsaturated zone at Yucca Mountain, Nevada. The goal of the effort was to produce a computational model that can be coupled to the project's calibrated 3D site-scale flow model so that the results of that effort could be incorporated directly into the Total System Performance Assessment (TSPA) analyses. The transport model simulates multiple species (typically 20 or more) with complex time-varying and spatially varying releases from the potential repository. Water-table rise, climate-change scenarios, and decay chains are additional features of the model. A cell-based particle-tracking method was employed that includes a dual-permeability formulation, advection, longitudinal dispersion, matrix diffusion, and colloid-facilitated transport. This paper examines the transport behavior of several key radionuclides through the unsaturated zone using the calibrated 3D unsaturated flow fields. Computational results illustrate the relative importance of fracture flow, matrix diffusion, and lateral diversion on the distribution of travel times from the simulated repository to the water table for various climatic conditions. Results also indicate rapid transport through fractures for a portion of the released mass. Further refinement of the model will address several issues, including conservatism in the transport model, the assignment of parameters in the flow and transport models, and the underlying assumptions used to support the conceptual models of flow and transport in the unsaturated zone at Yucca Mountain.