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The Making Introductory Courses Real while Online (MICRO) laboratory project was developed to meet the need for hands-on experiments, focused on topics in analytical chemistry, to be delivered safely remotely or in a socially distanced in-person lab. Unlike more traditional lab experiments, MICRO laboratories use only microgram or nanogram amounts of chemicals; paper microfluidic technology is used to store and mix reactants. Instructional materials use an inquiry-based approach and are situated in a context that highlights the human impacts of the scientific analysis. To support broader-scale implementation of the experiments and promote a shift to more inquiry-based laboratory instruction, an array of supports were developed, including adaptable instructional materials, instructional videos for lab preparation, resource guides, and an introductory workshop. A cohort of nine institutions implemented MICRO laboratories both remotely and in person during Fall 2020. Students were able to successfully complete the experiments, and the inquiry nature of the laboratories led to an increased comfort with the trial-and-error nature of authentic scientific practice. Additionally, most faculty participants indicated a commitment to an increased degree of inquiry in their laboratory pedagogy.

We have successfully developed a one-semester general chemistry course that meets the primary learning goals of the traditional two-semester sequence. It is appropriate for physical, life, and eart...

Capsaicin (CAP) activates the transient receptor potential vanilloid 1 (TRPV1) channel on sensory neurons, improving ATP production, vascular function, fatigue resistance, and thus exercise performance. However, the underlying mechanisms of CAP-induced ergogenic effects and fatigue-resistance, remain elusive. To evaluate the potential anti-fatigue effects of CAP, 10 young healthy males performed constant-load cycling exercise time to exhaustion (TTE) trials (85% maximal work rate) after ingestion of placebo (PL; fiber) or CAP capsules in a blinded, counterbalanced, crossover design, while cardiorespiratory responses were monitored. Fatigue was assessed with the interpolated twitch technique, pre-post exercise, during isometric maximal voluntary contractions (MVC). No significant differences (p > 0.05) were detected in cardiorespiratory responses and self-reported fatigue (RPE scale) during the time trial or in TTE (375 ± 26 and 327 ± 36 s, respectively). CAP attenuated the reduction in potentiated twitch (PL: −52 ± 6 vs. CAP: −42 ± 11%, p = 0.037), and tended to attenuate the decline in maximal relaxation rate (PL: −47 ± 33 vs. CAP: −29 ± 68%, p = 0.057), but not maximal rate of force development, MVC, or voluntary muscle activation. Thus, CAP might attenuate neuromuscular fatigue through alterations in afferent signaling or neuromuscular relaxation kinetics, perhaps mediated via the sarco-endoplasmic reticulum Ca2+ ATPase (SERCA) pumps, thereby increasing the rate of Ca2+ reuptake and relaxation.

The MICRO project has developed a series of active-learning labs that can be safely delivered to students either at home or in person using paper microfluidic technology. The skills covered in these labs are appropriate for sophomore-level analytical chemistry courses and general chemistry.

Assembly and bonding are major obstacles in manufacturing of functionally integrated fluidic devices. Here we demonstrate a single-material 3D printed device with an integrated porous structure capable of filtering particulate matter for the colourimetric detection of iron from soil and natural waters. Selecting a PolyJet 3D printer for its throughput, integrated filters were created exploiting a phenomenon occurring at the interface between the commercially available build material (Veroclear-RGD810) and water-soluble support material (SUP707). The porous properties were tuneable by varying the orientation of the print head relative to the channel and by varying the width of the build material. Porous structures ranging from 100 to 200 μm in thickness separated the sample and reagent chambers, filtering particles larger than 15 μm in diameter. Maintaining the manufacturing throughput of the Polyjet printer, 221 devices could be printed in 1.5 h (∼25 s per device). Including the 12 h post-processing soak in sodium hydroxide to remove the solid support material, the total time to print and process 221 devices was 13.5 h (3.6 min per device), with a material cost of $2.50 each. The applicability of the fluidic device for point of collection analysis was evaluated using colourimetric determination of iron from soil slurry and environmental samples. Following the reduction of Fe3+ to Fe2+ using hydroxylammonium chloride, samples were introduced to the fluidic device where particulate matter was retained by the filter, allowing for particulate-free imaging of the red complex formed with 1,10-phenanthroline using a smartphone camera. The calibration curve ranged from of 1-100 mg L-1 Fe2+ and good agreement (95%) was obtained between the point of collection device and Sector Field ICP-MS.

Mitochondrial dysfunction plays a significant role in neurodegenerative disease including ataxias and other movement disorders, particularly those marked by progressive degeneration in the cerebellum. In this study, we investigate the role of mitochondrial oxidative phosphorylation (OXPHOS) deficits in cerebellar tissue of a Purkinje cell-driven spinocerebellar ataxia type 1 (SCA1) mouse. Using RNA sequencing transcriptomics, OXPHOS complex assembly analysis and oxygen consumption assays, we report that in the presence of mutant polyglutamine-expanded ataxin-1, SCA1 mice display deficits in cerebellar OXPHOS complex I (NADH-coenzyme Q oxidoreductase). Complex I genes are upregulated at the time of symptom onset and upregulation persists into late stage disease; yet, functional assembly of complex I macromolecules are diminished and oxygen respiration through complex I is reduced. Acute treatment of postsymptomatic SCA1 mice with succinic acid, a complex II (succinate dehydrogenase) electron donor to bypass complex I dysfunction, ameliorated cerebellar OXPHOS dysfunction, reduced cerebellar pathology and improved motor behavior. Thus, exploration of mitochondrial dysfunction and its role in neurodegenerative ataxias, and warrants further investigation.

Mitochondrial dysfunction plays a significant role in the aging process and in neurodegenerative diseases including several hereditary spinocerebellar ataxias and other movement disorders marked by progressive degeneration of the cerebellum. The goal of this protocol is to assess mitochondrial dysfunction in Spinocerebellar ataxia type 1 (SCA1) and assess the efficacy of pharmacological targeting of metabolic respiration via the water-soluble compound succinic acid to slow disease progression. This approach is applicable to other cerebellar diseases and can be adapted to a host of water-soluble therapies. Ex vivo analysis of mitochondrial respiration is used to detect and quantify disease-related changes in mitochondrial function. With genetic evidence (unpublished data) and proteomic evidence of mitochondrial dysfunction in the SCA1 mouse model, we evaluate the efficacy of treatment with the water-soluble metabolic booster succinic acid by dissolving this compound directly into the home cage drinking water. The ability of the drug to pass the blood brain barrier can be deduced using high performance liquid chromatography (HPLC). The efficacy of these compounds can then be tested using multiple behavioral paradigms including the accelerating rotarod, balance beam test and footprint analysis. Cytoarchitectural integrity of the cerebellum can be assessed using immunofluorescence assays that detect Purkinje cell nuclei and Purkinje cell dendrites and soma. These methods are robust techniques for determining mitochondrial dysfunction and the efficacy of treatment with water-soluble compounds in cerebellar neurodegenerative disease.

Dynamic buffer conditions are present in many electrophoretically driven separations. Polyelectrolyte multilayer coatings have been employed in CE because of their chemical and physical stability as well as their ease of application. The goal of this study is to measure the effect of dynamic changes in buffer pH on flow using a real-time method for measuring EOF. Polyelectrolyte multilayers (PEMs) were composed of pairs of strong or completely ionized polyelectrolytes including poly(diallyldimethylammonium) chloride and poly(styrene sulfonate) and weak or ionizable polyelectrolytes including poly(allylamine) and poly(methacrylic acid). Polyelectrolyte multilayers of varying thicknesses (3, 4, 7, 8, 15, or 16 layers) were also studied. While the magnitude of the EOF was monitored every 2 s, the buffer pH was exchanged from a relatively basic pH (7.1) to increasingly acidic pHs (6.6, 6.1, 5.5, and 5.1). Strong polyelectrolytes responded minimally to changes in buffer pH ( 10%) and sometimes irreversible changes were measured with weak polyelectrolytes. Thicker coatings resulted in a similar magnitude of response but were more likely to degrade in response to buffer pH changes. The most stable coatings were formed from thinner layers of strong polyelectrolytes.

Although many chemistry students at small liberal arts colleges participate in undergraduate research projects with faculty members, they do not get much experience framing their own research questions and designing their own projects, which is an important part of science. We have implemented a developmental process to help students design and execute their own research projects in a two-course sequence: seminar in the fall and an integrated laboratory in the January term as a capstone experience in the chemistry curriculum. In seminar, students read scientific literature to generate an unanswered question that becomes the basis for a project proposal. Students then compare and contrast various methods to answer the question and propose a project. In the integrated laboratory, students execute the project where they troubleshoot experiments, collect and interpret data, and draw conclusions. Assessment of final papers and student course evaluations indicated that the students met the above goals. Overall, this educational experience can be implemented at other small liberal arts colleges and elements of this project could be adapted at a larger college or university.

Modern drug laws require that a seized sample be characterized for both the illegal substances present and the quantity of each of those substances. The goal of this work was to develop a common approach to model development based on Raman spectroscopic analysis followed by partial least squares (PLS) regression that would allow us to obtain quantitative information from simulated street-drug samples. Each drug sample contained one drug surrogate—either isoxsuprine, norephedrine, benzocaine, or lidocaine—and up to 3 different cutting agents. All spectra were acquired on a homebuilt Raman instrument equipped with a rotating sample holder. The same steps were employed for developing separate models for each drug surrogate, including spectral preprocessing by Savitsky-Golay smoothing, differentiation, mean-centering, and autoscaling. PLS models were developed using 2 latent variables that yielded root mean square errors of calibration (RMSEC) values in the 3% range and root mean square error of pred...

The ability to accurately and noninvasively analyze illicit drugs is important for criminal investigations and prosecution. Current methods involve significant sample pretreatment and most are destructive. The goal of this work is to develop a method based on Raman spectroscopy to classify simulated street drug mixtures composed of one drug component and up to three cutting agents including those routinely found in confiscated illicit street drug mixtures. Spectra were collected on both a homebuilt instrument using a HeNe laser and on a handheld commercial instrument with a 785 nm light source. Mixtures were prepared with drug concentrations ranging from 10 to 100 percent. Optimal preprocessing for the data set included truncating, Savitzky–Golay smoothing, normalization, differentiating, and mean centering. Using principal component analysis (PCA), it was possible to resolve the spectral differences between benzocaine, lidocaine, isoxsuprine, and norephedrine and correctly classify them 100 percent of the time.

CE separations are known for their high separation efficiencies. In systems with EOF, the high efficiencies benefit from the flat, plug profile that is characteristic of EOF. When a velocity gradient is present, such as in separations which have nonuniform buffer ionic strength, surface adsorption or differences in the height of the ends of the capillary, a parabolic flow component is introduced. This deviation from purely EOF yields increased peak dispersion and a subsequent decrease in separation performance. This work details a rapid method for detecting deviations from ideal plug flow during the course of a separation using the radially averaged flow profile of a photobleached fluorophore added to the BGE. By comparing the ratio of two different data analysis procedures, deviations from ideal plug flow can be detected. This method allows rapid measurement of flow character and does not interfere with the concurrent separation. We demonstrate easy detection of the onset of hydrodynamic flow induced by both gravity siphoning and an ionic strength buffer discontinuity. A brief analysis of the radially averaged peak shapes is also presented.

Insulin capture by a G-quadruplex DNA oligonucleotide containing a two-repeat sequence of the insulin-linked polymorphic region (ILPR) of the human insulin gene promoter region is reported. The immobilized oligonucleotide was demonstrated to capture human insulin from standard solutions and from nuclear extracts of pancreatic cells with high selectivity, using affinity MALDI-mass spectrometry and affinity capillary chromatography. Insulin was preferentially captured by the two-repeat ILPR oligonucleotide over another G-quadruplex forming oligonucleotide, the thrombin binding aptamer, as well as over a single repeat of the ILPR sequence that is not capable of forming the G-quadruplex architecture. Binding was shown to involve the beta chain of insulin, most likely through association with the two parallel loops of the G-quadruplex structure. The discovery raises the possibility that insulin may bind to G-quadruplex DNA formed in the ILPR in vivo and thereby play a role in modulation of insulin gene expression, and provides a basis for design of insulin analogs to probe this hypothesis. The availability of a DNA ligand to human insulin has analytical importance as well, offering an alternative to antibodies for in vitro or in vivo detection and sensing of insulin as well as its isolation and purification from biological samples.

Measurement of illicit drugs on paper currency is of interest for evidentiary purposes in legal cases involving the drug trade. Current methods, primarily based on mass spectrometry, are destructive and prevent re-analysis of the evidence. This article details a method based on Raman microspectroscopy that is able to collect spectra from individual crystals on the surface of paper currency. Mixtures of isoxsuprine and norephedrine, which are non-pharmacologically active drug surrogates, as well as lidocaine and benzocaine, common excipients in street drugs, were doped in small quantities onto US currency. Significant fluorescence interference resulted from the underlying dollar bill. This work presents two methods for reducing the fluorescence background, photobleaching and background subtraction, which both worked well. Finally, a method for determining the percent composition of individual components in heterogeneous mixtures was developed by systematically sampling the surface of the dollar bill. Results were accurate within a few percent, although the method was quite time consuming.

Drug consumption, and the industry that supports it, have been targets of law enforcement efforts for several decades. Recently, several countries have allowed the seizure of paper currency associated with the drug trade for evidentiary purposes. Mass spectrometric methods are most commonly used to detect the presence of illicit drugs on paper currency. Unfortunately, these methods are destructive and the evidence is no longer available for re‐analysis by other laboratories. Raman microspectroscopy provides an alternative for non‐invasively analyzing drug crystals on banknotes. This study shows that it is possible to detect and identify single drug crystals in a heterogeneous mixture. Samples were composed of two drug surrogates: isoxsuprine and norephedrine, and two common excipients: benzocaine and lidocaine. It is possible to detect and identify individual crystals on both microscope slides and paper currency. Spectra acquired from crystals on United States paper currency suffer from significa...

In 2008, the American Chemical Society’s (ACS) Committee on Professional Training (CPT) issued new guidelines for the approval of undergraduate chemistry programs. Undergraduate research continues to meet the requirements for a portion of laboratory hours necessary for a certified degree, and can also contribute to the in-depth course requirements. The CPT supplements on undergraduate research, excellent and rigorous undergraduate programs, and student skills expand on the pedagogical advantages of undergraduate research. The ACS Guidelines and CPT supplements are supportive of the important role that a research-supportive curriculum can play in the development and training of chemistry students. Departments interested in establishing or strengthening research-rich environments can find support from the ACS Guidelines and from the resources available through the Council on Undergraduate Research (CUR).

The insulin-linked polymorphic region (ILPR) of the human insulin gene contains tandem repeats of similar G-rich sequences, some of which form intramolecular G-quadruplex structures in vitro. Previous work showed affinity binding of insulin to an intramolecular G-quadruplex formed by ILPR variant a. Here, we report on interactions of insulin and the highly homologous insulin-like growth factor-2 (IGF-2) with ILPR variants a, h, and i. Circular dichroism indicated intramolecular G-quadruplex formation for variants a and h. Affinity MALDI MS and surface plasmon resonance were used to compare protein capture and binding strengths. Insulin and IGF-2 exhibited high binding affinity for variants a and h but not i, indicating the involvement of intramolecular G-quadruplexes. Interaction between insulin and variant a was unique in the appearance of two binding interactions with K(D) approximately 10(-13) M and K(D) approximately 10(-7) M, which was not observed for insulin with variant h (K(D) approximately 10(-8) M) or IGF-2 with either variant (K(D)s approximately 10(-9) M). The results provide a basis for the design of DNA binding ligands for insulin and IGF-2 and support a new approach to discovery of DNA affinity binding ligands based on genome-inspired sequences rather than the traditional combinatorial selection route to aptamer discovery.

Electroosmotic flow dynamics during a field-amplified sample stacking experiment have been studied experimentally using the periodic photobleaching of a dilute, neutral fluorophore added to the separation buffer. The effects of hydrodynamically injecting different sample plug lengths containing a mixture of arsenic compounds dissolved in 0.125 mM (120, 240, and 600 s) and 41.7 microM (27, 45, and 74 s) phosphate buffer with a separation buffer concentration of 12.5 mM phosphate buffer were examined. Changes in electroosmotic flow during sample stacking and separation were monitored at a rate of 1 Hz. The observed effects of increasing the sample plug length on electroosmotic flow and electrophoretic current agreed qualitatively with predictions by theoretical models presented in the literature. Electroosmotic flow changes on the order of 100% (1.6-3.3 mm/s) were observed. Broadening of the flow monitoring peaks has been used to examine parabolic flow due to the discontinuous buffer systems used for sample stacking.

The Council on Undergraduate Research (CUR) and the National Conferences on Undergraduate Research (NCUR) have officially joined forces under the CUR banner. Building on a long-standing alliance, the joint organization will be a leading voice for undergraduate research both within the academic community and with external constituencies. The merged organization will also continue to support undergraduate research students through the annual NCUR meeting, and faculty mentors through publications, institutes, advocacy efforts, and the biannual national meeting, among other resources.