Anomalously enhanced ion transport and uptake in functionalized angstrom-scale two-dimensional channels.

Emulating angstrom-scale dynamics of the highly selective biological ion channels is a challenging task. Recent work on angstrom-scale artificial channels has expanded our understanding of ion transport and uptake mechanisms under confinement. However, the role of chemical environment in such channels is still not well understood. Here, we report the anomalously enhanced transport and uptake of ions under confined MoS2-based channels that are ~five angstroms in size. The ion uptake preference in the MoS2-based channels can be changed by the selection of surface functional groups and ion uptake sequence due to the interplay between kinetic and thermodynamic factors that depend on whether the ions are mixed or not prior to uptake. Our work offers a holistic picture of ion transport in 2D confinement and highlights ion interplay in this regime.

Generation and Implementation of Continuum Infrared Pulses for Broadband Detection in 2D IR Spectroscopy.

In recent years, new methods of generating continuum mid-infrared pulses through filamentation in gases have been developed for ultrafast time-resolved infrared vibrational spectroscopy. The generated infrared pulses can have thousands of wavenumbers of bandwidth, spanning the entire mid-IR region while retaining pulse length below 100 fs. This technology has had a significant impact on problems involving ultrafast structural dynamics in congested spectra with broad features, such as those found in aqueous solutions and molecules with strong intermolecular interactions. This study describes the recent advances in generating and characterizing these pulses and the practical aspects of implementing these sources for broadband detection in transient absorption and 2D IR spectroscopy.

Amplification of mid-IR continuum for broadband 2D IR spectroscopy.

We report the generation and characterization of microjoule level, broad bandwidth femtosecond pulses in the mid-infrared (MIR) using optical parametric amplification of continuum MIR seed pulses in GaSe. The signal (3 µm) and idler (6 µm) pulses have energies of 6 µJ and 3 µJ with bandwidths of ∼950 cm-1 and 650 cm-1 FWHM and pulse lengths of 34 fs and 80 fs. Broadband 2D IR spectra of O-H and N-H transitions are acquired with the signal beam demonstrating the capabilities of this source for cross peak and line shape measurements.

Retrospective Study of Treatment Patterns and Natural History of Patients with T1a/b N0 Triple-Negative Breast Cancers: A Single-Institution Experience.

INTRODUCTION: T1a/b, node-negative (node-), triple-negative breast cancers (TNBCs) are underrepresented in randomized drug-approving clinical trials. Given their low incidence, the clinicopathological features, natural history, and treatment patterns of these tumors remain insufficiently understood. METHODS: We conducted a single-institution retrospective cohort study of patients with T1a/b, N0, M0 TNBCs. Deidentified patient- and tumor-related data were collected and summarized. Kruskal-Wallis, χ2, or Fisher exact tests were used to evaluate associations of interest. Kaplan-Meier methods, log-rank tests, and Cox's proportional hazards models were applied for survival analyses. RESULTS: Of 108 cases of node- TNBCs measuring ≤2 cm, 34 node- T1a/b tumors were included in our analysis. All cases had an intermediate to high histological grade, and most had a Ki-67 score of ≥20%. All patients received adjuvant chemotherapy, and many underwent mastectomy (47%). Docetaxel combined with cyclophosphamide was the most common adjuvant chemotherapy regimen (75%). We did not observe significant associations between improved outcomes and treatment with anthracycline-containing regimens. Among patients with node- pT1a/b tumors, the estimated 3-year recurrence-free survival (RFS) and distant RFS rates were both 96.3% (95% CI: 76.5-99.5), and the overall survival rate was estimated to be 100% (95% CI: 100-100). There were no cases of local recurrences observed. CONCLUSIONS: In our cohort, all patients with T1a/b node- TNBCs were treated with adjuvant chemotherapy and had favorable outcomes even when treated with anthracycline-sparing regimens.

Is Clostridium perfringens epsilon toxin associated with multiple sclerosis?

Clostridium perfringens epsilon toxin is associated with enterotoxaemia in livestock. More recently, it is proposed to play a role in multiple sclerosis (MS) in humans. Compared to matched controls, strains of C. perfringens which produce epsilon toxin are significantly more likely to be isolated from the gut of MS patients and at significantly higher levels; similarly, sera from MS patients are significantly more likely to contain antibodies to epsilon toxin. Epsilon toxin recognises the myelin and lymphocyte (MAL) protein receptor, damaging the blood-brain barrier and brain cells expressing MAL. In the experimental autoimmune encephalomyelitis model of MS, the toxin enables infiltration of immune cells into the central nervous system, inducing an MS-like disease. These studies provide evidence that epsilon toxin plays a role in MS, but do not yet fulfil Koch's postulates in proving a causal role.

Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport.

The structure, chemistry, and charge of interfaces between materials and aqueous fluids play a central role in determining properties and performance of numerous water systems. Sensors, membranes, sorbents, and heterogeneous catalysts almost uniformly rely on specific interactions between their surfaces and components dissolved or suspended in the water-and often the water molecules themselves-to detect and mitigate contaminants. Deleterious processes in these systems such as fouling, scaling (inorganic deposits), and corrosion are also governed by interfacial phenomena. Despite the importance of these interfaces, much remains to be learned about their multiscale interactions. Developing a deeper understanding of the molecular- and mesoscale phenomena at water/solid interfaces will be essential to driving innovation to address grand challenges in supplying sufficient fit-for-purpose water in the future. In this Review, we examine the current state of knowledge surrounding adsorption, reactivity, and transport in several key classes of water/solid interfaces, drawing on a synergistic combination of theory, simulation, and experiments, and provide an outlook for prioritizing strategic research directions.

Robotic-assisted foregut surgery is associated with lower rates of complication and shorter post-operative length of stay.

BACKGROUND: Two of the most common foregut operations are laparoscopic Heller myotomy and laparoscopic Nissen fundoplication. Robotic assistance, compared to standard laparoscopic approach, may potentially grant surgeons advantages such as enhanced visualization and dexterity. This study compares patient outcomes for Heller myotomy (HM) and Nissen fundoplication (NF) when performed laparoscopically versus robotically. METHODS: A retrospective review of patients at a single institution who underwent laparoscopic or robotic-assisted HM or NF from January 2019 to July 2022 was conducted. 123 HM (72 laparoscopic, 51 robotic-assisted) and 92 NF (62 laparoscopic, 30 robotic-assisted) were performed by three surgeons. Outcomes investigated were operative time, hospital length of stay, pre- and post-operative imaging, resolution of symptoms at 30 days, resolution of symptoms at 90 days, and complications. RESULTS: In the HM cohorts, the average operative time was longer in the robotic cohort (127 min robotic versus 108 min laparoscopic, p < 0.01). However, overall complication rates (p < 0.05) were lower, and hospital length of stay was shorter in the robotic group (1.5 days compared to 2.7 days, p < 0.001). In the NF cohorts, there was no significant difference in operative time. However, hospital length of stay was shorter in the robotic group (1.54 days compared to 2.7 days, p < 0.001) with otherwise similar outcomes. There was no difference in the rate of post-operative resolution of symptoms or need for additional interventions in either HM or NF. CONCLUSION: Robotic-assisted HM and NF are associated with shorter hospital stays compared to their respective laparoscopic approaches. Robotic-assisted HM also has a lower rate of complications. Our findings suggest that robotic assistance may be beneficial for shortening hospital length of stay and decreasing complications for certain surgeries specific to Foregut surgery.

Exchange-Mediated Transport in Battery Electrolytes: Ultrafast or Ultraslow?

Understanding the mechanisms of charge transport in batteries is important for the rational design of new electrolyte formulations. Persistent questions about ion transport mechanisms in battery electrolytes are often framed in terms of vehicular diffusion by persistent ion-solvent complexes versus structural diffusion through the breaking and reformation of ion-solvent contacts, i.e., solvent exchange events. Ultrafast two-dimensional (2D) IR spectroscopy can probe exchange processes directly via the evolution of the cross-peaks on picosecond time scales. However, vibrational energy transfer in the absence of solvent exchange gives rise to the same spectral signatures, hiding the desired processes. We employ 2D IR on solvent resonances of a mixture of acetonitrile isotopologues to differentiate chemical exchange and energy-transfer dynamics in a comprehensive series of Li+, Mg2+, Zn2+, Ca2+, and Ba2+ bis(trifluoromethylsulfonyl)imide electrolytes from the dilute to the superconcentrated regime. No exchange phenomena occur within at least 100 ps, regardless of the ion identity, salt concentration, and presence of water. All of the observed spectral dynamics originate from the intermolecular energy transfer. These results place the lower experimental boundary on the ion-solvent residence times to several hundred picoseconds, much slower than previously suggested. With the help of MD simulations and conductivity measurements on the Li+ and Zn2+ systems, we discuss these results as a continuum of vehicular and structural modalities that vary with concentration and emphasize the importance of collective electrolyte motions to ion transport. These results hold broadly applicable to many battery-relevant ions and solvents.

Benefits of implementing student-led review and mock examinations in the medical undergraduate gross anatomy curriculum.

Anatomy consists of material that continually defines a student's undergraduate medical curriculum, and thus attaining a solid understanding of it is critical for academic success. Student exposure to anatomy prior to matriculation to the United States (US) medical school is highly variable, with some first introduced to the material in medical school. As a result, students without foundation in anatomy can struggle with adapting to the self-directed learning style that is required to excel with a prosection-based (i.e. hands-off analysis of a cadaver previously dissected by a professional) approach. In this study, second-year US medical students who have previously excelled in the first-year courses at the University of South Florida Morsani College of Medicine (in collaboration with faculty advisors) designed and offered a mock practical examination that mirrors the official practical exam specific to each course: a timed practical examination using dissected human cadavers and radiological imaging to assess anatomical knowledge, followed by a review session. Since the mock practical and review session was designed from a student's perspective, the material could be tailored to specifically address topics that students historically have struggled with. Students who participated in the mock practical and associated review sessions reported feeling more confident than their peers who did not participate. In addition, they significantly outperformed their peers on the official practical examination, independent of any demographic factors or educational background. This study demonstrates the benefits of incorporating peer-assisted learning (PAL) into the anatomical component of the medical school curriculum.

Imaging Utilization Patterns and Injury Characteristics Associated with Electric Standing Scooters in a Major Urban Area.

BACKGROUND: The recent proliferation of electric standing scooters in major urban areas of the United States has been accompanied by injuries of varying severity and nature, representing a growing public health concern. OBJECTIVE: Our aim was to characterize imaging utilization patterns for injuries associated with electric scooter (e-scooter) use, including their initial emergency department (ED) management. METHODS: We conducted a retrospective review of the electronic medical record for all patients presenting to affiliated EDs for e-scooter-related injuries between July 2018 and April 2020. Demographics, date and time of presentation, imaging study type, resultant injury, and procedural details were recorded. RESULTS: Ninety-seven patients were included; mean age was 27.6 years. Of these, 55 patients (57%) had injuries identified on imaging and 40% of all imaging studies were positive. Most identified injuries (61%) were musculoskeletal, with a small number of neurological (2%) and genitourinary (1%) injuries. The highest prevalence of presentations occurred in August; most patients (72%) presented between 3 pm and 1 am and granular peaks were between 12 am and 1 am and 5 pm and 6 pm. CONCLUSIONS: Patients presenting with e-scooter injuries have a high likelihood of injury to the radial head, nasal bone, and malleoli. Emergency physicians should be especially vigilant for injuries in these areas at presentation. Visceral injuries are uncommon but may be severe enough to warrant surgery.

Structural Characterization of Protonated Water Clusters Confined in HZSM-5 Zeolites.

A molecular description of the structure and behavior of water confined in aluminosilicate zeolite pores is a crucial component for understanding zeolite acid chemistry under hydrous conditions. In this study, we use a combination of ultrafast two-dimensional infrared (2D IR) spectroscopy and ab initio molecular dynamics (AIMD) to study H2O confined in the pores of highly hydrated zeolite HZSM-5 (∼13 and ∼6 equivalents of H2O per Al atom). The 2D IR spectrum reveals correlations between the vibrations of both terminal and H-bonded O-H groups and the continuum absorption of the excess proton. These data are used to characterize the hydrogen-bonding network within the cluster by quantifying single-, double-, and non-hydrogen-bond donor water molecules. These results are found to be in good agreement with the statistics calculated from an AIMD simulation of an H+(H2O)8 cluster in HZSM-5. Furthermore, IR spectral assignments to local O-H environments are validated with DFT calculations on clusters drawn from AIMD simulations. The simulations reveal that the excess charge is detached from the zeolite and resides near the more highly coordinated water molecules in the cluster. When they are taken together, these results unambiguously assign the complex IR spectrum of highly hydrated HZSM-5, providing quantitative information on the molecular environments and hydrogen-bonding topology of protonated water clusters under extreme confinement.

Intraosseous gout mimicking giant cell tumor of the patella.

Intraosseous gout involving the patella is an unusual presentation of the common inflammatory crystal deposition disease. In most reported cases of gout in the patella, there is prominent involvement of the adjacent patellar or quadriceps tendons of the extensor mechanism. A report from Japan describes another pattern of deposition, with a lesion arising in the synchondrosis of a bipartite patella. We present a case of a patient with no known history of gout experiencing vague anterior knee pain and subtle but rapidly progressive findings of a patellar lucent lesion on radiographs. No other cause for the patient's pain was identified on imaging. No prominent involvement of surrounding tendinous structures on MRI, unipartite patellar morphology, normal serum uric acid levels, rapid growth, and nonspecific appearance of the lesion led to a working diagnosis of patellar giant cell tumor. Biopsy of the lesion was performed to guide further management, which yielded the unexpected result of crystalline deposits consistent with gout.

Evidence of Clostridium perfringens epsilon toxin associated with multiple sclerosis.

BACKGROUND: It was recently reported that, using Western blotting, some multiple sclerosis (MS) patients in the United States had antibodies against epsilon toxin (Etx) from Clostridium perfringens, suggesting that the toxin may play a role in the disease. OBJECTIVE: We investigated for serum antibodies against Etx in UK patients with clinically definite multiple sclerosis (CDMS) or presenting with clinically isolated syndrome (CIS) or optic neuritis (ON) and in age- and gender-matched controls. METHODS: We tested sera from CDMS, CIS or ON patients or controls by Western blotting. We also tested CDMS sera for reactivity with linear overlapping peptides spanning the amino acid sequence (Pepscan) of Etx. RESULTS: Using Western blotting, 24% of sera in the combined CDMS, CIS and ON groups ( n = 125) reacted with Etx. In the control group ( n = 125), 10% of the samples reacted. Using Pepscan, 33% of sera tested reacted with at least one peptide, whereas in the control group only 16% of sera reacted. Out of 61 samples, 21 (43%) were positive to one or other testing methodology. Three samples were positive by Western blotting and Pepscan. CONCLUSION: Our results broadly support the previous findings and the role of Etx in the aetiology of MS warrants further investigation.

Two-dimensional electronic vibrational spectroscopy and ultrafast excitonic and vibronic photosynthetic energy transfer.

Two-dimensional electronic-vibrational (2DEV) spectroscopy is a new coherent spectroscopic technique, which shows considerable promise for unravelling complex molecular dynamics. In this Discussion we describe an application to the energy transfer pathway in the major light harvesting protein, LHCII, providing new data on the center line slopes (CLS) of the spectral peaks. The CLS provides information that appears unique to the 2DEV method. We then outline a general approach to calculating 2DEV spectra which is valid for strongly and weakly coupled molecular systems. We conclude with some prospects for the future development of 2DEV spectroscopy and its theoretical analysis.

Two-dimensional electronic-vibrational spectroscopic study of conical intersection dynamics: an experimental and electronic structure study.

The relaxation from the lowest singlet excited state of the triphenylmethane dyes, crystal violet and malachite green, is studied via two-dimensional electronic-vibrational (2DEV) spectroscopy. After excitation of the dyes at their respective absorption maxima, the ensuing excited state dynamics are tracked by monitoring the C[double bond, length as m-dash]C aromatic stretch. With the aid of electronic structure calculations, the observed transitions in the 2DEV spectra are assigned to specific geometries and a detailed story of the evolution of the nuclear wavepacket as it diffuses on the excited state potential energy surface (PES) and ultimately passes through the conical intersection is developed. Notably, it is revealed that the relaxation of the lowest singlet excited state involves intramolecular charge transfer while the nuclear wavepacket is on the excited state PES. Finally, through analyzing the center line slopes of the measured peaks, we show how both solvent motions and changes in the molecular dipole moment affect the correlation between electronic and vibrational degrees of freedom. This work clearly demonstrates the usefulness of 2DEV spectroscopy in following the motion of nuclear wavepackets after photoexcitation and in studying the interactions between the molecular dipole moment and surrounding solvent environment.

Entropic barriers in the kinetics of aqueous proton transfer.

Aqueous proton transport is uniquely rapid among aqueous processes, mediated by fluctuating hydrogen bond reorganization in liquid water. In a process known as Grotthuss diffusion, the excess charge diffuses primarily by sequential proton transfers between water molecules rather than standard Brownian motion, which explains the anomalously high electrical conductivity of acidic solutions. Employing ultrafast IR spectroscopy, we use the orientational anisotropy decay of the bending vibrations of the hydrated proton complex to study the picosecond aqueous proton transfer kinetics as a function of temperature, concentration, and counterion. We find that the orientational anisotropy decay exhibits Arrhenius behavior, with an apparent activation energy of 2.4 kcal/mol in 1M and 2M HCl. Interestingly, acidic solutions at high concentration with longer proton transfer time scales display corresponding decreases in activation energy. We interpret this counterintuitive trend by considering the entropic and enthalpic contributions to the activation free energy for proton transfer. Halide counteranions at high concentrations impose entropic barriers to proton transfer in the form of constraints on the solution's collective H-bond fluctuations and obstruction of potential proton transfer pathways. The corresponding proton transfer barrier decreases due to weaker water-halide H-bonds in close proximity to the excess proton, but the entropic effects dominate and result in a net reduction in the proton transfer rate. We estimate the activation free energy for proton transfer as ∼1.0 kcal/mol at 280 K.

A review of the global distribution of Alexandrium minutum (Dinophyceae) and comments on ecology and associated paralytic shellfish toxin profiles, with a focus on Northern Europe.

Alexandrium minutum is a globally distributed harmful algal bloom species with many strains that are known to produce paralytic shellfish toxins (PSTs) and consequently represent a concern to human and ecosystem health. This review highlights that A. minutum typically occurs in sheltered locations, with cell growth occurring during periods of stable water conditions. Sediment characteristics are important in the persistence of this species within a location, with fine sediments providing cyst deposits for ongoing inoculation to the water column. Toxic strains of A. minutum do not produce a consistent toxin profile, different populations produce a range of PSTs in differing quantities. Novel cluster analysis of published A. minutum toxin profiles indicates five PST profile clusters globally. Some clusters are grouped geographically (Northern Europe) while others are widely spread. Isolates from Taiwan have a range of toxin profile clusters and this area appears to have the most diverse set of PST producing A. minutum populations. These toxin profiles indicate that within the United Kingdom there are two populations of A. minutum grouping with strains from Northern France and Southern Ireland. There is a degree of interconnectivity in this region due to oceanic circulation and a high level of shipping and recreational boating. Further research into the interrelationships between the A. minutum populations in this global region would be of value.

Correlating the motion of electrons and nuclei with two-dimensional electronic-vibrational spectroscopy.

Multidimensional nonlinear spectroscopy, in the electronic and vibrational regimes, has reached maturity. To date, no experimental technique has combined the advantages of 2D electronic spectroscopy and 2D infrared spectroscopy, monitoring the evolution of the electronic and nuclear degrees of freedom simultaneously. The interplay and coupling between the electronic state and vibrational manifold is fundamental to understanding ensuing nonradiative pathways, especially those that involve conical intersections. We have developed a new experimental technique that is capable of correlating the electronic and vibrational degrees of freedom: 2D electronic-vibrational spectroscopy (2D-EV). We apply this new technique to the study of the 4-(di-cyanomethylene)-2-methyl-6-p-(dimethylamino)styryl-4H-pyran (DCM) laser dye in deuterated dimethyl sulfoxide and its excited state relaxation pathways. From 2D-EV spectra, we elucidate a ballistic mechanism on the excited state potential energy surface whereby molecules are almost instantaneously projected uphill in energy toward a transition state between locally excited and charge-transfer states, as evidenced by a rapid blue shift on the electronic axis of our 2D-EV spectra. The change in minimum energy structure in this excited state nonradiative crossing is evident as the central frequency of a specific vibrational mode changes on a many-picoseconds timescale. The underlying electronic dynamics, which occur on the hundreds of femtoseconds timescale, drive the far slower ensuing nuclear motions on the excited state potential surface, and serve as a excellent illustration for the unprecedented detail that 2D-EV will afford to photochemical reaction dynamics.

Role of prostate artery embolization in the management of refractory haematuria of prostatic origin.

Prostatic haematuria is among the most common genitourinary complaints of emergency room visits, distressing and troublesome to men and a challenging clinical problem to the treating physician. The most common aetiologies of prostatic haematuria include benign prostatic hyperplasia and prostate cancer. Prostatic haematuria usually resolves with conservative and medical methods; failure of these interventions results in refractory haematuria of prostatic origin (RHPO), a potentially life-threatening scenario. Several different treatments have been described, with varying degrees of success. Patients with RHPO are often elderly and unfit for radical surgery. Prostate artery embolization (PAE) has evolved as a safe and effective technique in the management of RHPO. Use of a superselective approach optimizes clinical success while minimizing complications. This minimally invasive approach improves patients with haemodynamic instability, serves as a bridge to elective surgery, and is a highly effective treatment for RHPO. It may obviate the need for more invasive and morbid surgical therapies. The aim of the present review was to describe the current management of RHPO and the technique of PAE and to review its efficacy and associated morbidity.