Acute Intracranial Subdural Hematoma Masquerading as a Postpartum Headache: A Case Report.

INTRODUCTION: An acute subdural hematoma is a collection of blood in the space between the dural and arachnoid membranes overlying the brain. Head trauma is the most common cause. Less frequently, low cerebrospinal fluid pressure, due to a spontaneous or iatrogenic cerebrospinal fluid leak can result in a subdural hematoma. CASE REPORT: We discuss the case of a 26-year-old woman who presented with a frontal headache following epidural anesthesia for vaginal delivery. The differential diagnosis included spinal headache, postpartum hypercoagulability, dural sinus thrombosis, and intracranial hemorrhage or mass. Her vital signs and physical examination were normal. A computed tomography of the brain revealed an acute subdural hematoma along the left frontal cerebral hemisphere, without midline shift or mass effect. A blood patch was placed with complete resolution of her symptoms. CONCLUSION: This case illustrates an unusual case of an acute subdural hematoma in the postpartum period following epidural anesthesia for labor pain management. It was thought to be caused by intracranial hypotension following epidural anesthesia and a cerebrospinal fluid leak.

Vaginal Swelling After Intercourse: A Case Report.

INTRODUCTION: A vulvar hematoma is a hemorrhagic fluid collection in the female external genitalia. The majority occur as an obstetrical complication, especially during labor. Non-obstetrical vulvar hematomas are usually the result of trauma, with coitus being the most common etiology. CASE REPORT: We present the case of a 25-year-old woman with significant vaginal pain and swelling after vigorous sexual intercourse. She exhibited tenderness and swelling of the left labia majora and minora. The differential diagnosis included bleeding, abscess, and deep venous thrombosis. Laboratory studies were normal and computed tomography of the pelvis indicated the swelling was most likely due to blood. The patient was taken to the operating room, and approximately 150 cubic centimeters of clot was evacuated. The patient had an uneventful recovery and was discharged home the next day. CONCLUSION: This case illustrates the unique presentation and challenges in making the diagnosis of vulvar hematoma.

Electrochemical Strategy for Low-Cost Viral Detection.

Sexually transmitted infections, including the human immunodeficiency virus (HIV) and the human papillomavirus (HPV), disproportionally impact those in low-resource settings. Early diagnosis is essential for managing HIV. Similarly, HPV causes nearly all cases of cervical cancer, the majority (90%) of which occur in low-resource settings. Importantly, infection with HPV is six times more likely to progress to cervical cancer in women who are HIV-positive. An inexpensive, adaptable point-of-care test for viral infections would make screening for these viruses more accessible to a broader set of the population. Here, we report a novel, cost-effective electrochemical platform using gold leaf electrodes to detect clinically relevant viral loads. We have combined this platform with loop-mediated isothermal amplification and a CRISPR-based recognition assay to detect HPV. Lower limits of detection were demonstrated down to 104 total copies of input nucleic acids, which is a clinically relevant viral load for HPV DNA. Further, proof-of-concept experiments with cervical swab samples, extracted using standard extraction protocols, demonstrated that the strategy is extendable to complex human samples. This adaptable technology could be applied to detect any viral infection rapidly and cost-effectively.

Iron oxide xerogels for improved water quality monitoring of arsenic(III) in resource-limited environments via solid-phase extraction, preservation, storage, transportation, and analysis of trace contaminants (SEPSTAT).

Arsenic is a widespread trace groundwater contaminant that presents a range of health risks and has an acceptable level of only 10 µg L-1 in drinking water. However, in many countries arsenic quantification in water is limited to centralized laboratories because it requires the use of elemental analysis techniques with high capital cost. As a result, routine water samples are frequently not tested for trace contaminants such as arsenic. In order to facilitate improved arsenic monitoring, we present the use of iron oxide xerogels for adsorption of arsenic(iii) from water samples at neutral pH, dry storage for over 120 days, and desorption of stored arsenic at elevated pH. Iron oxide xerogels offer high surface area (340 m2 g-1) and an As(iii) adsorption capacity of 165 mg g-1. Using an extraction solution of 100 mM sodium hydroxide and 1 mM sodium phosphate, As(iii) is reliably eluted from iron oxide xerogels for initial As(iii) concentrations from 10 µg L-1 to 1000 µg L-1, with a calculated detection limit of less than 4 µg L-1 and less than 17% difference in recovered As(iii) between test solutions with low and high interfering ion concentrations. By demonstrating the ability for iron oxide xerogels to reliably adsorb, store, and release arsenic, we enable the development of protocols for solid-phase extraction, preservation, storage, transportation, and analysis of trace contaminants (SEPSTAT), where arsenic would be adsorbed from water samples onto xerogel-based sorbents and shipped to centralized laboratories for recovery and quantification.

Solid-Phase Extraction, Preservation, Storage, Transport, and Analysis of Trace Contaminants for Water Quality Monitoring of Heavy Metals.

Accurate quantification of trace contaminants currently requires collection, preservation, and transportation of large volumes (250-1000 mL) of water to centralized laboratories, which impedes monitoring of trace-level pollutants in many resource-limited environments. To overcome this logistical challenge, we propose a new paradigm for trace contaminant monitoring based on dry preservation: solid-phase extraction, preservation, storage, transport, and analysis of trace contaminants (SEPSTAT). We show that a few grams of low-cost, commercially available cation exchange resin can be repurposed to extract heavy metal cations from water samples even in the presence of background ions, dryly preserve these cations for at least 24 months, and release them by acid elution for accurate quantification. A compact, human-powered device incorporating the sorbent removes spiked contaminants from real water samples in a few minutes. The device can be stored and transported easily and produces a sample suitable for measurement by standard methods, predicting the original sample heavy metal concentration generally within an error of 15%. These results suggest that, by facilitating the collection, storage, handling, and transportation of water samples and by enabling cost-effective use of high-throughput capital-intensive instruments, SEPSTAT has the potential to increase the ease and reach of water quality monitoring of trace contaminants.

Fieldwork-based determination of design priorities for point-of-use drinking water quality sensors for use in resource-limited environments.

Improved capabilities in microfluidics, electrochemistry, and portable assays have resulted in the development of a wide range of point-of-use sensors intended for environmental, medical, and agricultural applications in resource-limited environments of developing countries. However, these devices are frequently developed without direct interaction with their often-remote intended user base, creating the potential for a disconnect between users' actual needs and those perceived by sensor developers. As different analytical techniques have inherent strengths and limitations, effective measurement solution development requires determination of desired sensor attributes early in the development process. In this work, we present our findings on design priorities for point-of-use microbial water sensors based on fieldwork in rural India, as well as a guide to fieldwork methodologies for determining desired sensor attributes. We utilized group design workshops for initial identification of design priorities, and then conducted choice-based conjoint analysis interviews for quantification of user preferences among these priorities. We found the highest user preference for integrated reporting of contaminant concentration and recommended actions, as well as significant preferences for mostly reusable sensor architectures, same-day results, and combined ingredients. These findings serve as a framework for future microbial sensor development and a guide for fieldwork-based understanding of user needs.

In-field determination of soil ion content using a handheld device and screen-printed solid-state ion-selective electrodes.

Small-holding farmers in the developing world suffer from sub-optimal crop yields because they lack a soil diagnostic system that is affordable, usable, and actionable. This paper details the fabrication and characterization of an integrated point-of-use soil-testing system, comprised of disposable ion-selective electrode strips and a handheld electrochemical reader. Together, the strips and reader transduce soil ion concentrations into to an alphanumeric output that can be communicated via text message to a central service provider offering immediate, customized fertilizer advisory. The solid-state ion-selective electrode (SS-ISE) strips employ a two-electrode design with screen-printable carbon nanotube ink serving as the electrical contacts for the working and reference electrodes. The working electrode comprises a plasticizer-free butyl acrylate ion-selective membrane (ISM), doped with an ion-selective ionophore and lipophilic salt. Meanwhile, the reference electrode includes a screen-printed silver-silver chloride ink and a polyvinyl-butyral membrane, which is doped with sodium chloride for stable reference potentials. As a proof of concept, potassium-selective electrodes are studied, given potassium's essential role in plant growth and reproduction. The ISE-based system is reproducibly manufactured to yield a Nernstian response with a sub-micromolar detection limit (pK+ of 5.18 ± 0.08) and near-Nernstian sensitivity (61 mV/decade) in the presence of a 0.02 M strontium chloride extraction solution. Analysis of soil samples using the printed electrodes and reader yielded a correlation coefficient of 𝑅2 = 0.89 with respect to values measured via inductively coupled plasma atomic emission spectroscopy (ICP-AES). The reliable performance of this system is encouraging toward its deployment for soil nutrient management in resource-limited environments.

Measurement of lipid accumulation in Chlorella vulgaris via flow cytometry and liquid-state ¹H NMR spectroscopy for development of an NMR-traceable flow cytometry protocol.

In this study, we cultured Chlorella vulgaris cells with a range of lipid contents, induced via nitrogen starvation, and characterized them via flow cytometry, with BODIPY 505/515 as a fluorescent lipid label, and liquid-state 1H NMR spectroscopy. In doing so, we demonstrate the utility of calibrating flow cytometric measurements of algal lipid content using triacylglyceride (TAG, also known as triacylglycerol or triglyceride) content per cell as measured via quantitative 1H NMR. Ensemble-averaged fluorescence of BODIPY-labeled cells was highly correlated with average TAG content per cell measured by bulk NMR, with a linear regression yielding a linear fit with r2 = 0.9974. This correlation compares favorably to previous calibrations of flow cytometry protocols to lipid content measured via extraction, and calibration by NMR avoids the time and complexity that is generally required for lipid quantitation via extraction. Flow cytometry calibrated to a direct measurement of TAG content can be used to investigate the distribution of lipid contents for cells within a culture. Our flow cytometry measurements showed that Chlorella vulgaris cells subjected to nitrogen limitation exhibited higher mean lipid content but a wider distribution of lipid content that overlapped the relatively narrow distribution of lipid content for replete cells, suggesting that nitrogen limitation induces lipid accumulation in only a subset of cells. Calibration of flow cytometry protocols using direct in situ measurement of TAG content via NMR will facilitate rapid development of more precise flow cytometry protocols, enabling investigation of algal lipid accumulation for development of more productive algal biofuel feedstocks and cultivation protocols.

Detection of algal lipid accumulation due to nitrogen limitation via dielectric spectroscopy of Chlamydomonas reinhardtii suspensions in a coaxial transmission line sample cell.

In this study, dielectric characterization of algae cell suspensions was used to detect lipid accumulation due to nitrogen starvation. Wild-type Chlamydomonas reinhardtii (CC-125) was cultivated in replete and nitrogen-limited conditions in order to achieve a range of lipid contents, as confirmed by Nile Red fluorescence measurements. A vector network analyzer was used to measure the dielectric scattering parameters of a coaxial region of concentrated cell suspension. The critical frequency fc of the normalized transmission coefficient |S21(*)| decreased with increasing lipid content but did not change with cell concentration. These observations were consistent with a decrease in cytoplasmic conductivity due to lipid accumulation in the preliminary transmission line model. This dielectric sensitivity to lipid content will facilitate the development of a rapid, noninvasive method for algal lipid measurement that could be implemented in industrial settings without the need for specialized staff and analytical facilities.

Occupational exposure to airborne asbestos from phenolic molding material (Bakelite) during sanding, drilling, and related activities.

In this study, a historical phenolic (Bakelite) molding material, BMMA-5353, was tested to determine the airborne concentrations of asbestos fibers released during four different activities (sawing, sanding, drilling, and cleanup of dust generated from these activities). Each activity was performed for 30 min, often in triplicate. The primary objective for testing BMMA-5353 was to quantitatively determine the airborne concentration of asbestos fibers, if any, in the breathing zone of workers. Uses of this product typically did not include sawing or sanding, but it may have been drilled occasionally. For this reason, only small quantities were sawed, sanded, and drilled in this simulation study. Personal (n = 40), area (n = 80), and background/clearance (n = 88) air samples were collected during each activity and analyzed for total fiber concentrations using phase contrast microscopy (PCM) and, for asbestos fiber counts, transmission electron microscopy (TEM). The raw PCM-total fiber concentrations were adjusted based on TEM analyses that reported the fraction of asbestos fibers, to derive a PCM-asbestos concentration that would enable calculation of an 8-hour time-weighted average (TWA). The estimated 8-hour TWAs ranged from 0.006 to 0.08 fibers per cubic centimeter using a variety of worker exposure scenarios. Therefore, assuming an exposure scenario in which a worker uses power tools to cut and sand products molded from BMMA-5353 and similar products in the manner evaluated in this study, airborne asbestos concentrations should not exceed current or historical occupational exposure limits.

Hyperpolarized helium-3 MR imaging of pulmonary function.

Recent advances in HP MR imaging contrast agents have led to novel tests of pulmonary function. Many of these tests show promise in the clinical arena.

Occupational exposure to airborne asbestos from coatings, mastics, and adhesives.

Over the past few years, a question has arisen about the degree of exposure to airborne asbestos associated with the application, cleanup, and tear-out of glues and mastics used between 1940 and the present. These liquid products were used either to adhere insulation to pipes and boilers or to cover the insulation so as to protect it. In this study, four asbestos-containing products, a coating, two mastics, and an adhesive, which were representative of the various classes of products that have been used historically, were tested to determine the airborne concentration of asbestos fibers released during five different activities (application, spill cleanup, sanding, removal, and sweep cleaning). Each activity was performed for 30 min (often in triplicate). Personal (n=172) and area (n=280) air samples were collected during the tests, and each was analyzed for total fiber concentrations using phase contrast microscopy (PCM), and for asbestos fiber count using transmission electron microscopy (TEM). A measurable concentration of asbestos fibers was detected in six of the 452 samples collected (0.0017-0.0184 fibers/ml). The observed asbestos fibers counts for each product were similar to background. Only one asbestos fiber was detected in an indoor background sample; no asbestos fibers were identified in any of the outdoor background samples. The (raw) PCM-total fiber concentrations were adjusted based on TEM analyses that reported fraction of asbestos fibers (to derive a PCM-asbestos concentration) and by the fraction of the 8-h workday that a worker spends performing the activity (to derive a calculated TWA). For the coatings, mastics, and adhesives evaluated in the present study, the calculated TWAs using hypothetical work scenarios were well below the current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 0.1 fibers/ml. The calculated TWAs ranged from 0.03 to 0.009 fibers/ml. The actual concentration of airborne asbestos due to these products is almost certainly much less than the TWAs, and may be so low as to not be measurable. These results support the historical view that these products, over the past 50 years, did not pose an occupational health hazard under foreseeable uses.

Relations among joint attention, amount of intervention and language gain in autism.

The purpose of the present study was to investigate the unconditional and conditional relations between amount of intervention and language development in children with autism. Joint attention skills were proposed as child characteristics that might moderate this relation. The results replicated previous findings that better joint attention skills were associated with greater language development. The results further indicated that the relation between amount of intervention and gain in language age was conditional; it depended upon the child's ability to respond to bids for joint attention from others and initial language skills. The current study demonstrated the utility of employing characteristics of children as moderators of relations between interventions and developmental outcomes.