Real-time tracking of coherent oscillations of electrons in a nanodevice by photo-assisted tunnelling.

Coherent collective oscillations of electrons excited in metallic nanostructures (localized surface plasmons) can confine incident light to atomic scales and enable strong light-matter interactions, which depend nonlinearly on the local field. Direct sampling of such collective electron oscillations in real-time is crucial to performing petahertz scale optical modulation, control, and readout in a quantum nanodevice. Here, we demonstrate real-time tracking of collective electron oscillations in an Au bowtie nanoantenna, by recording photo-assisted tunnelling currents generated by such oscillations in this quantum nanodevice. The collective electron oscillations show a noninstantaneous response to the driving laser fields with a T2 decay time of nearly 8 femtoseconds. The contributions of linear and nonlinear electron oscillations in the generated tunnelling currents were precisely determined. A phase control of electron oscillations in the nanodevice is illustrated. Functioning in ambient conditions, the excitation, phase control, and read-out of coherent electron oscillations pave the way toward on-chip light-wave electronics in quantum nanodevices.

Imaging and controlling coherent phonon wave packets in single graphene nanoribbons.

The motion of atoms is at the heart of any chemical or structural transformation in molecules and materials. Upon activation of this motion by an external source, several (usually many) vibrational modes can be coherently coupled, thus facilitating the chemical or structural phase transformation. These coherent dynamics occur on the ultrafast timescale, as revealed, e.g., by nonlocal ultrafast vibrational spectroscopic measurements in bulk molecular ensembles and solids. Tracking and controlling vibrational coherences locally at the atomic and molecular scales is, however, much more challenging and in fact has remained elusive so far. Here, we demonstrate that the vibrational coherences induced by broadband laser pulses on a single graphene nanoribbon (GNR) can be probed by femtosecond coherent anti-Stokes Raman spectroscopy (CARS) when performed in a scanning tunnelling microscope (STM). In addition to determining dephasing (~440 fs) and population decay times (~1.8 ps) of the generated phonon wave packets, we are able to track and control the corresponding quantum coherences, which we show to evolve on time scales as short as ~70 fs. We demonstrate that a two-dimensional frequency correlation spectrum unequivocally reveals the quantum couplings between different phonon modes in the GNR.

Complex spinal dysraphism: myelomenigocele associated with dorsal bony spur, split cord malformation type I, syringomyelia, lipoma and tethered cord.

Variations in split cord malformation (SCM) are known. However, association of SCM type I with myelomeningocele along with same level dorsal bony spur has not been described previously. We report a 1-year old male child who presented with these findings with associated syringomyelia, lipoma and tethered cord.

Multiple Primary Bilateral Cerebral Echinococcosis in an Adult: A Neurological Rarity.

Although cases of intracranial hydatid cysts are commonly encountered, majority of them are secondary and are seen in children. Primary bilateral multiple intracranial hydatid cysts in adults are a neurological rarity. Intracranial involvement usually occurs following infestation of the other organs in the body by the pathogen. Multiple lesions in brain can manifest either following rupture of a single parent cyst in brain or by systemic dissemination from other organs. Here, we are presenting an adult patient who underwent successful surgical removal of multiple primary hydatid cysts of brain. A 47-year-old male patient presented with features of raised intracranial pressure and other focal deficits. Magnetic resonance imaging showed multiple cystic lesions on both sides of the cerebrum. Similar primary lesions elsewhere in the body were ruled out by other investigations. He underwent successful surgical removal of all the lesions. Intraoperative picture and histology were suggestive of hydatid cyst. In published literature, there are very few cases similar to ours. Echinococcosis should be considered as a differential diagnosis in multiple cystic lesions of the brain in endemic areas. Early diagnosis, proper surgical technique, and standard antihelminthic drug regimen are the key to achieve good outcome in these patients.

Embolization of the Middle Meningeal Artery for the Treatment of Chronic Subdural Hematoma: A Path Less Travelled So Far.

Introduction Chronic subdural hematoma (CSDH) is relatively common and usually encountered in elderly population. With steady increase in life expectancy, incidence of CSDH also is bound to increase proportionately. Though surgery is the treatment of choice and relatively a simpler procedure, recurrence is a cause of concern. Embolization of the middle meningeal artery (MMA) is a newly evolving treatment modality in CSDH and offers hope in some of the recently published case series. Materials and Methods Five cases of CSDH were subjected to embolization of MMA over a period from October 2019 to July 2020. Among them, it was employed for treatment in four cases after at least two recurrences following surgery, and in one case, it was done as the patient was not fit for surgery. All procedures were done under general anesthesia and polyvinyl alcohol (PVA) particles were used for embolization. Follow-up of the patients were done with computed tomography brain at 4 weeks and after 6 months of the procedure. Results There was no incidence of recurrence in our series. Furthermore, embolization per se did not cause any complication or side effect which could be directly attributable to the procedure itself. Conclusion In carefully selected patients based on clinical profile and angiographic findings, MMA embolization can be an effective modality for the treatment in CSDH.

Intracranial Myopericytoma: A Rare Benign Tumor at an Extremely Rare Location.

A 50-year-old female presented with a history of seizures, headache, nausea, and vomiting. On imaging, parafalcine meningioma with mass effect features was rendered. She underwent right frontal tumor excision and craniotomy. Pathological examination showed a tumor composed of syncytial aggregates of round to plump fusiform cells forming whorls around prominent branching congested vessels. The tumorous cells expressed α-smooth actin and heavy-chain caldesmon and were negative for epithelial membrane antigen, protein S100, HMB45, CD34, calponin, and desmin, thus providing the final diagnosis of intracranial myopericytoma. The rarity of this benign tumor at an extremely rare location prompted this study. As preoperative radiological investigations are nonspecific in such cases, a detailed and comprehensive pathological examination is mandatory to come to a definitive diagnosis.

Ultrashort Pulse Excited Tip-Enhanced Raman Spectroscopy in Molecules.

Vibrational fingerprints of molecules and low-dimension materials can be traced with subnanometer resolution by performing Tip-enhanced Raman spectroscopy (TERS) in a scanning tunneling microscope (STM). Strong atomic-scale localization of light in the plasmonic nanocavity of the STM enables high spatial resolution in STM-TERS; however, the temporal resolution is so far limited. Here, we demonstrate stable TERS measurements from subphthalocyanine (SubPc) molecules excited by ∼500 fs long laser pulses in a low-temperature (LT) ultrahigh-vacuum (UHV) STM. The intensity of the TERS signal excited with ultrashort pulses scales linearly with the increasing flux of the laser pulses and exponentially with the decreasing gap-size of the plasmonic nanocavity. Furthermore, we compare the characteristic features of TERS excited with ultrashort pulses and with a continuous-wave (CW) laser. Our work lays the foundation for future experiments of time-resolved femtosecond TERS for the investigation of molecular dynamics with utmost spatial, temporal, and energy resolutions simultaneously.

Efficacy and Outcome of Embolization of Intracranial Meningiomas With Minimal Resources.

BACKGROUND: Preoperative embolization of intracranial meningiomas is an accepted treatment modality and offers many advantages for subsequent surgery. It has also been used as a primary therapy without subsequent surgery in selected cases. In this study, the authors share their experience of this procedure with minimal resources carried out in cases where definitive surgery was not advisable. METHODS: This is a prospective study of 6 cases of meningiomas treated over a period of 11 months (November 2020 to September 2021). None of the cases were fit for prolonged surgery under general anesthesia and also had certain comorbid conditions. Embolization was done in a setup with limited resources without a fully equipped catheterization lab. Post-procedure magnetic resonance imaging (MRI) was done within 48 hours of the procedure. Follow-up was done in the outpatient department. RESULTS: There was complete disappearance of tumor blush in all the 6 cases. Immediate post-procedure MRI revealed significant necrosis of the tumor cavity. Three cases succumbed to their primary comorbid conditions and in the other cases follow-up was uneventful. Following embolization, clinical improvement of presenting symptoms was seen in all 6 cases. CONCLUSIONS: In resource-restricted settings, by introducing such innovative methods it is possible to perform selected endovascular procedures. Embolization can be used as a primary treatment modality avoiding subsequent surgery in selected cases with a good outcome.

The World Health Organization Collaborating Center for Emergency and Trauma (WHO-CCET) in South East Asia, The World Academic Council of Emergency Medicine (WACEM), and The American College of Academic International Medicine (ACAIM) 2021 Framework for using Telemedicine Technology at Healthcare Institutions.

The coronavirus disease 2019 crisis has forced the world to integrate telemedicine into health delivery systems in an unprecedented way. To deliver essential care, lawmakers, physicians, patients, payers, and health systems have all adopted telemedicine and redesigned delivery processes with accelerated speed and coordination in a fragmented way without a long-term vision or uniformed standards. There is an opportunity to learn from the experiences gained by this pandemic to help shape a better health-care system that standardizes telemedicine to optimize the overall efficiency of remote health-care delivery. This collaboration focuses on four pillars of telemedicine that will serve as a framework to enable a uniformed, standardized process that allows for remote data capture and quality, aiming to improve ongoing management outside the hospital. In this collaboration, we recommend learning from this experience by proposing a telemedicine framework built on the following four pillars-patient safety and confidentiality; metrics, analytics, and reform; recording of audio-visual data as a health record; and reimbursement and accountability.

Ultrafast Photon-Induced Tunneling Microscopy.

Unification of the techniques of ultrafast science and scanning tunneling microscopy (STM) has the potential of tracking electronic motion in molecules simultaneously in real space and real time. Laser pulses can couple to an STM junction either in the weak-field or in the strong-field interaction regime. The strong-field regime entails significant modification (dressing) of the tunneling barrier of the STM junction, whereas the weak-field or the photon-driven regime entails perturbative interaction. Here, we describe how photons carried in an ultrashort pulse interact with an STM junction, defining the basic fundamental framework of ultrafast photon-induced tunneling microscopy. Selective dipole coupling of electronic states by photons is shown to be controllable by adjusting the DC bias at the STM junction. An ultrafast tunneling microscopy involving photons is established. Consolidation of the technique calls for innovative approaches to detect photon-induced tunneling currents at the STM junction. We introduce and characterize here three techniques involving dispersion, polarization, and frequency modulation of the laser pulses to lock-in detect the laser-induced tunneling current. We show that photon-induced tunneling currents can simultaneously achieve angstrom scale spatial resolution and sub-femtosecond temporal resolution. Ultrafast photon-induced tunneling microscopy will be able to directly probe electron dynamics in complex molecular systems, without the need of reconstruction techniques.

An International Virtual Classroom: The Emergency Department Experience at Weill Cornell Medicine and Weill Bugando Medical Center in Tanzania.

Emergency medicine (EM) is rapidly being recognized as a specialty around the globe. This has particular promise for low- and middle-income countries (LMICs) that experience the largest burden of disease for emergency conditions. Specialty education and training in EM remain essentially an apprenticeship model. Finding the required expertise to educate graduate learners can be challenging in regions where there are low densities of specialty providers.We describe an initiative to implement a sustainable, bidirectional partnership between the Emergency Medicine Departments of Weill Cornell Medicine (WCM) in New York, NY, USA, and Bugando Medical Center (BMC) in Mwanza, Tanzania. We used synchronous and asynchronous telecommunication technology to enhance an ongoing emergency medicine education collaboration.The Internet infrastructure for this collaboration was created by bolstering 4G services available in Mwanza, Tanzania. By maximizing the 4G signal, sufficient bandwidth could be created to allow for live 2-way audio/video communication. Using synchronous and asynchronous applications such as Zoom and WhatsApp, providers at WCM and BMC can attend real-time didactic lectures, participate in discussion forums on clinical topics, and collaborate on the development of clinical protocols. Proof of concept exercises demonstrated that this system can be used for real-time mentoring in EKG interpretation and ultrasound technique, for example. This system was also used to share information and develop operations flows during the COVID-19 pandemic. The use of telecommunication technology and e-learning in a format that promotes long-term, sustainable interaction is practical and innovative, provides benefit to all partners, and should be considered as a mechanism by which global partnerships can assist with training in emergency medicine in LMICs.

Answering the Challenge of COVID-19 Pandemic Through Innovation and Ingenuity.

The novel coronavirus disease 2019 (COVID-19) pandemic has created a maelstrom of challenges affecting virtually every aspect of global healthcare system. Critical hospital capacity issues, depleted ventilator and personal protective equipment stockpiles, severely strained supply chains, profound economic slowdown, and the tremendous human cost all culminated in what is questionably one of the most profound challenges that humanity faced in decades, if not centuries. Effective global response to the current pandemic will require innovation and ingenuity. This chapter discusses various creative approaches and ideas that arose in response to COVID-19, as well as some of the most impactful future trends that emerged as a result. Among the many topics discussed herein are telemedicine, blockchain technology, artificial intelligence, stereolithography, and distance learning.

Intracranial Myopericytoma: A Rare Benign Tumor at an Extremely Rare Location.

A 50-year-old female with a history of seizures, headache, nausea, and vomiting. On imaging, parafalcine meningioma with mass effect features was rendered. She underwent right frontal tumor excision and craniotomy. Pathological examination showed a tumor composed of syncytial aggregates of round to plump fusiform cells forming whorls around prominent branching congested vessels. The tumorous cells expressed alpha-smooth muscle actin and heavy chain caldesmon and were negative for epithelial membrane antigen, protein S100, HMB45, CD34, calponin and desmin, thus providing the final diagnosis of intracranial myopericytoma. The rarity of this benign tumor at an extremely location, prompted this study. As preoperative radiological investigations are nonspecific in such cases, hence a detailed and comprehensive pathological examination is mandatory to come to a definitive diagnosis.

Emergence of Extended-Spectrum ß-Lactamase Urinary Tract Infections Among Hospitalized Emergency Department Patients in the United States.

STUDY OBJECTIVE: Enterobacteriaceae resistant to ceftriaxone, mediated through extended-spectrum ß-lactamases (ESBLs), commonly cause urinary tract infections worldwide, but have been less prevalent in North America. Current US rates are unknown. We determine Enterobacteriaceae antimicrobial resistance rates among US emergency department (ED) patients hospitalized for urinary tract infection. METHODS: We prospectively enrolled adults hospitalized for urinary tract infection from 11 geographically diverse university-affiliated hospital EDs during 2018 to 2019. Among participants with culture-confirmed infection, we evaluated prevalence of antimicrobial resistance, including that caused by ESBL-producing Enterobacteriaceae, resistance risk factors, and time to in vitro-active antibiotics. RESULTS: Of 527 total participants, 444 (84%) had cultures that grew Enterobacteriaceae; 89 of 435 participants (20.5%; 95% confidence interval 16.9% to 24.5%; 4.6% to 45.4% by site) whose isolates had confirmatory testing had bacteria that were ESBL producing. The overall prevalence of ESBL-producing Enterobacteriaceae infection among all participants with urinary tract infection was 17.2% (95% confidence interval 14.0% to 20.7%). ESBL-producing Enterobacteriaceae infection risk factors were hospital, long-term care, antibiotic exposure within 90 days, and a fluoroquinolone- or ceftriaxone-resistant isolate within 1 year. Enterobacteriaceae resistance rates for other antimicrobials were fluoroquinolone 32.3%, gentamicin 13.7%, amikacin 1.3%, and meropenem 0.3%. Ceftriaxone was the most common empirical antibiotic. In vitro-active antibiotics were not administered within 12 hours of presentation to 48 participants (53.9%) with ESBL-producing Enterobacteriaceae infection, including 17 (58.6%) with sepsis. Compared with other Enterobacteriaceae infections, ESBL infections were associated with longer time to in vitro-active treatment (17.3 versus 3.5 hours). CONCLUSION: Among adults hospitalized for urinary tract infection in many US locations, ESBL-producing Enterobacteriaceae have emerged as a common cause of infection that is often not initially treated with an in vitro-active antibiotic.

Short Term Home Oxygen Therapy for COVID-19 patients: The COVID-HOT algorithm.

Innovative solutions are required to effectively address the unprecedented surge of demand on our healthcare systems created by the COVID-19 pandemic. Home treatment and monitoring of patients who are asymptomatic or mildly symptomatic can be readily implemented to ameliorate the health system burden while maintaining safety and effectiveness of care. Such endeavor requires careful triage and coordination, telemedicine and technology support, workforce and education, as well as robust infrastructure. In the understandable paucity of evidence-based, protocolized approaches toward HOT for COVID-19 patients, our group has created the current document based on the cumulative experience of members of the Joint ACAIM-WACEM COVID-19 Clinical Management Taskforce. Utilizing available evidence-based resources and extensive front-line experience, the authors have suggested a pragmatic pathway for providing safe and effective home oxygen therapy in the community setting.

Not that kind of tree: Assessing the potential for decision tree-based plant identification using trait databases.

PREMISE: Advancements in machine learning and the rise of accessible "big data" provide an important opportunity to improve trait-based plant identification. Here, we applied decision-tree induction to a subset of data from the TRY plant trait database to (1) assess the potential of decision trees for plant identification and (2) determine informative traits for distinguishing taxa. METHODS: Decision trees were induced using 16 vegetative and floral traits (689 species, 20 genera). We assessed how well the algorithm classified species from test data and pinpointed those traits that were important for identification across diverse taxa. RESULTS: The unpruned tree correctly placed 98% of the species in our data set into genera, indicating its promise for distinguishing among the species used to construct them. Furthermore, in the pruned tree, an average of 89% of the species from the test data sets were properly classified into their genera, demonstrating the flexibility of decision trees to also classify new species into genera within the tree. Closer inspection revealed that seven of the 16 traits were sufficient for the classification, and these traits yielded approximately two times more initial information gain than those not included. DISCUSSION: Our findings demonstrate the potential for tree-based machine learning and big data in distinguishing among taxa and determining which traits are important for plant identification.

The 2019-2020 Novel Coronavirus (Severe Acute Respiratory Syndrome Coronavirus 2) Pandemic: A Joint American College of Academic International Medicine-World Academic Council of Emergency Medicine Multidisciplinary COVID-19 Working Group Consensus Paper.

What started as a cluster of patients with a mysterious respiratory illness in Wuhan, China, in December 2019, was later determined to be coronavirus disease 2019 (COVID-19). The pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel Betacoronavirus, was subsequently isolated as the causative agent. SARS-CoV-2 is transmitted by respiratory droplets and fomites and presents clinically with fever, fatigue, myalgias, conjunctivitis, anosmia, dysgeusia, sore throat, nasal congestion, cough, dyspnea, nausea, vomiting, and/or diarrhea. In most critical cases, symptoms can escalate into acute respiratory distress syndrome accompanied by a runaway inflammatory cytokine response and multiorgan failure. As of this article's publication date, COVID-19 has spread to approximately 200 countries and territories, with over 4.3 million infections and more than 290,000 deaths as it has escalated into a global pandemic. Public health concerns mount as the situation evolves with an increasing number of infection hotspots around the globe. New information about the virus is emerging just as rapidly. This has led to the prompt development of clinical patient risk stratification tools to aid in determining the need for testing, isolation, monitoring, ventilator support, and disposition. COVID-19 spread is rapid, including imported cases in travelers, cases among close contacts of known infected individuals, and community-acquired cases without a readily identifiable source of infection. Critical shortages of personal protective equipment and ventilators are compounding the stress on overburdened healthcare systems. The continued challenges of social distancing, containment, isolation, and surge capacity in already stressed hospitals, clinics, and emergency departments have led to a swell in technologically-assisted care delivery strategies, such as telemedicine and web-based triage. As the race to develop an effective vaccine intensifies, several clinical trials of antivirals and immune modulators are underway, though no reliable COVID-19-specific therapeutics (inclusive of some potentially effective single and multi-drug regimens) have been identified as of yet. With many nations and regions declaring a state of emergency, unprecedented quarantine, social distancing, and border closing efforts are underway. Implementation of social and physical isolation measures has caused sudden and profound economic hardship, with marked decreases in global trade and local small business activity alike, and full ramifications likely yet to be felt. Current state-of-science, mitigation strategies, possible therapies, ethical considerations for healthcare workers and policymakers, as well as lessons learned for this evolving global threat and the eventual return to a "new normal" are discussed in this article.