Factors Influencing the Repeated Transient Optical Droplet Vaporization Threshold and Lifetimes of Phase Change, Perfluorocarbon Nanodroplets.

Perfluorocarbon nanodroplets (PFCnDs) are sub-micrometer emulsions composed of a surfactant-encased perfluorocarbon (PFC) liquid and can be formulated to transiently vaporize through optical stimulation. However, the factors governing repeated optical droplet vaporization (ODV) have not been investigated. In this study, we employ high-frame-rate ultrasound (US) to characterize the ODV thresholds of various formulations and imaging parameters and identify those that exhibit low vaporization thresholds and repeatable vaporization. We observe a phenomenon termed "preconditioning", where initial laser pulses generate reduced US contrast that appears linked with an increase in nanodroplet size. Variation in laser pulse repetition frequency is found not to change the vaporization threshold, suggesting that "preconditioning" is not related to residual heat. Surfactants (bovine serum albumin, lipids, and zonyl) impact the vaporization threshold and imaging lifetime, with lipid shells demonstrating the best performance with relatively low thresholds (21.6 ± 3.7 mJ/cm2) and long lifetimes (t1/2 = 104 ± 21.5 pulses at 75 mJ/cm2). Physiological stiffness does not affect the ODV threshold and may enhance nanodroplet stability. Furthermore, PFC critical temperatures are found to correlate with vaporization thresholds. These observations enhance our understanding of ODV behavior and pave the way for improved nanodroplet performance in biomedical applications.

Quantum simulation of exact electron dynamics can be more efficient than classical mean-field methods.

Quantum algorithms for simulating electronic ground states are slower than popular classical mean-field algorithms such as Hartree-Fock and density functional theory but offer higher accuracy. Accordingly, quantum computers have been predominantly regarded as competitors to only the most accurate and costly classical methods for treating electron correlation. However, here we tighten bounds showing that certain first-quantized quantum algorithms enable exact time evolution of electronic systems with exponentially less space and polynomially fewer operations in basis set size than conventional real-time time-dependent Hartree-Fock and density functional theory. Although the need to sample observables in the quantum algorithm reduces the speedup, we show that one can estimate all elements of the k-particle reduced density matrix with a number of samples scaling only polylogarithmically in basis set size. We also introduce a more efficient quantum algorithm for first-quantized mean-field state preparation that is likely cheaper than the cost of time evolution. We conclude that quantum speedup is most pronounced for finite-temperature simulations and suggest several practically important electron dynamics problems with potential quantum advantage.

A UK-wide study to describe resource consumption and waste management practices in skin surgery including Mohs micrographic surgery.

BACKGROUND: There is a lack of national guidance specifying how skin surgery, including Mohs micrographic surgery (MMS), should be conducted, leading to a degree of heterogeneity in the set-up of skin surgery services and how skin surgeries are performed. OBJECTIVES: To provide the first UK-wide cross-sectional study reporting real-world data on the set-up and waste management practices of skin surgery, including MMS. METHODS: A UK-wide service evaluation study was conducted between 1 March 2022 and 30 June 2022 using a standardized data collection pro forma. Twelve participating sites from England, Northern Ireland, Scotland and Wales provided data from 115 skin surgery lists involving 495 patients and 547 skin surgery procedures between 1 March 2022 and 30 June 2022. RESULTS: Mean total weight of nonsharps skin surgery waste was 0.52 kg per procedure (0.39 kg clinical waste, 0.05 kg general waste and 0.08 kg recycling waste). Data from a single site using disposable surgical instruments reported a mean of only 0.25 kg of sharps waste per procedure. The recycling rate ranged between 0% and 44% across the cohort with a mean recycling rate of 16%. CONCLUSIONS: We advocate that staff transition to the British Society of Dermatological Surgery 2022 sustainability guidance, which made wide-ranging recommendations to facilitate staff to transition to sustainable practices in skin surgery.

The Drosophila spectraplakin Short stop regulates focal adhesion dynamics by cross-linking microtubules and actin.

The spectraplakin family of proteins includes ACF7/MACF1 and BPAG1/dystonin in mammals, VAB-10 in Caenorhabditis elegans, Magellan in zebrafish, and Short stop (Shot), the sole Drosophila member. Spectraplakins are giant cytoskeletal proteins that cross-link actin, microtubules, and intermediate filaments, coordinating the activity of the entire cytoskeleton. We examined the role of Shot during cell migration using two systems: the in vitro migration of Drosophila tissue culture cells and in vivo through border cell migration. RNA interference (RNAi) depletion of Shot increases the rate of random cell migration in Drosophila tissue culture cells as well as the rate of wound closure during scratch-wound assays. This increase in cell migration prompted us to analyze focal adhesion dynamics. We found that the rates of focal adhesion assembly and disassembly were faster in Shot-depleted cells, leading to faster adhesion turnover that could underlie the increased migration speeds. This regulation of focal adhesion dynamics may be dependent on Shot being in an open confirmation. Using Drosophila border cells as an in vivo model for cell migration, we found that RNAi depletion led to precocious border cell migration. Collectively, these results suggest that spectraplakins not only function to cross-link the cytoskeleton but may regulate cell-matrix adhesion.

Fermionic Partial Tomography via Classical Shadows.

We propose a tomographic protocol for estimating any k-body reduced density matrix (k-RDM) of an n-mode fermionic state, a ubiquitous step in near-term quantum algorithms for simulating many-body physics, chemistry, and materials. Our approach extends the framework of classical shadows, a randomized approach to learning a collection of quantum-state properties, to the fermionic setting. Our sampling protocol uses randomized measurement settings generated by a discrete group of fermionic Gaussian unitaries, implementable with linear-depth circuits. We prove that estimating all k-RDM elements to additive precision ϵ requires on the order of (n/k)k^{3/2}log(n)/ϵ^{2} repeated state preparations, which is optimal up to the logarithmic factor. Furthermore, numerical calculations show that our protocol offers a substantial improvement in constant overheads for k≥2, as compared to prior deterministic strategies. We also adapt our method to particle-number symmetry, wherein the additional circuit depth may be halved at the cost of roughly 2-5 times more repetitions.

Formulation and Acoustic Modulation of Optically Vaporized Perfluorocarbon Nanodroplets.

Microbubbles are the most commonly used imaging contrast agent in ultrasound. However, due to their size, they are limited to vascular compartments. These microbubbles can be condensed or formulated as perfluorocarbon nanodroplets (PFCnDs) that are small enough to extravasate and then be triggered acoustically at the target site. These nanoparticles can be further enhanced by including an optical absorber such as near infrared organic dye or nanoparticles (e.g., copper sulfide nanoparticles or gold nanoparticles/nanorods). Optically tagged PFCnDs can be vaporized through laser irradiation in a process known as optical droplet vaporization (ODV). This process of activation enables the use of high boiling point perfluorocarbon cores, which cannot be vaporized acoustically under the maximum mechanical index threshold for diagnostic imaging. Higher boiling point cores result in droplets that will recondense after vaporization, resulting in "blinking" PFCnDs that briefly produce contrast after vaporization before condensing back into nanodroplet form. This process can be repeated to produce contrast on demand, allowing for the background free imaging, multiplexing, super-resolution, and contrast enhancement through both optical and acoustic modulation. This article will demonstrate how to synthesize optically-triggerable, lipid shell PFCnDs utilizing probe sonication, create polyacrylamide phantoms to characterize the nanodroplets, and acoustically modulate the PFCnDs after ODV to improve contrast.

Leveraging the Imaging Transmit Pulse to Manipulate Phase-Change Nanodroplets for Contrast-Enhanced Ultrasound.

Phase-change perfluorohexane nanodroplets (PFHnDs) are a new class of recondensable submicrometer-sized contrast agents that have potential for contrast-enhanced and super-resolution ultrasound imaging with an ability to reach extravascular targets. The PFHnDs can be optically triggered to undergo vaporization, resulting in spatially stationary, temporally transient microbubbles. The vaporized PFHnDs are hyperechoic in ultrasound imaging for several to hundreds of milliseconds before recondensing to their native, hypoechoic, liquid nanodroplet state. The decay of echogenicity, i.e., the dynamic behavior of the ultrasound signal from optically triggered PFHnDs in ultrasound imaging, can be captured using high-frame-rate ultrasound imaging. We explore the possibility to manipulate the echogenicity dynamics of optically triggered PFHnDs in ultrasound imaging by changing the phase of the ultrasound imaging pulse. Specifically, the ultrasound imaging system was programmed to transmit two imaging pulses with inverse polarities. We show that the imaging pulse phase can affect the amplitude and the temporal behavior of PFHnD echogenicity in ultrasound imaging. The results of this study demonstrate that the ultrasound echogenicity is significantly increased (about 78% improvement) and the hyperechoic timespan of optically triggered PFHnDs is significantly longer (about four times) if the nanodroplets are imaged by an ultrasound pulse starting with rarefactional pressure versus a pulse starting with compressional pressure. Our finding has direct and significant implications for contrast-enhanced ultrasound imaging of droplets in applications such as super-resolution imaging and molecular imaging where detection of individual or low-concentration PFHnDs is required.

Use of Ivermectin in Neurocysticercosis: A Case Report.

BACKGROUND Neurocysticercosis is a Taenia solium infection which utilizes the tapeworm as a vector and humans as a definitive host and causes development of cystic lesions in the central nervous system. The current established medical therapy is albendazole with praziquantel as a secondary agent, but results can be mixed depending on each patient and their form of neurocysticercosis. CASE REPORT We present a case pertaining to a young female patient diagnosed with single parenchymal neurocysticercosis based on clinical and diagnostic findings. This case was unique in the sense that ivermectin, another antiparasitic agent, was used as monotherapy with significant improvement in the patient's clinical presentation and radiological findings. CONCLUSIONS Despite current guidelines recommending use of albendazole with or without praziquantel for neurocysticercosis, our case (as well as 4 other cases documented in the recent past) suggest a possible use of ivermectin as potential therapy for neurocysticercosis. We recommend continued research regarding other cases of ivermectin use in similar patients and even comparison studies with albendazole with or without praziquantel in terms of efficacy and side effects in order to better treat this international endemic.

Case report: Mycobacterium bovis orchitis post intravesical Bacillus Calmette Guerin.

Bacillus Calmette-Guérin (BCG) therapy is a common adjunctive therapy for superficial bladder carcinoma but there has been noted to be complications from this treatment ranging from general disseminated infections to osteomuscular involvement. We report a case regarding a 63 year old gentleman who presented with right testicular swelling and pain and later found to have evidence consistent with Mycobacterium bovis orchitis. We also detail a literature review regarding genitourinary infections secondary to BCG therapy and discussion regarding current testing modalities.

Lemierre's syndrome: Case report and brief literature review.

Lemierre's syndrome has been shown to be increasing in incidence in the past 20 years with one popular suggesting that said rise occurred from less aggressive antibacterial coverage. We report a case of Lemierre's syndrome and also reviewed the 15 most recent case reports. A previously healthy 25 year old male who initially developed sore throat and flu-like symptoms, was prescribed antibacterials as an outpatient but was hospitalized for worsening symptoms. He was later diagnosed with Lemierre's syndrome and improved clinically with IV antimicrobials alone. From our concise literature review, we determined that a decrease in antibiotic prescriptions may not fully explain why the incidence of Lemierre's has been increasing. Thus, future research should be focused in evaluating possible worsening susceptibilities to antibiotics and improvements on detection. We also advise physicians to be aware of the signs and symptoms of this rare but potentially fatal condition as well as the available detection methods and treatment.

Plesiomonas shigelloides Septic Shock Leading to Death of Postsplenectomy Patient with Pyruvate Kinase Deficiency and Hemochromatosis.

Although Plesiomonas shigelloides, a water-borne bacterium of the Enterobacteriaceae family, usually causes self-limiting gastroenteritis with diarrhea, several cases of sepsis have been reported. We report the case of a 43-year-old male patient with hemochromatosis, pyruvate kinase deficiency, and asplenia via splenectomy who developed septic shock caused by P. shigelloides complicated by respiratory failure, renal failure, liver failure, and disseminated intravascular coagulation. Early aggressive antimicrobial therapy and resuscitation measures were unsuccessful and the patient passed away. We kindly suggest clinicians to implement early diagnosis of septic shock, empirical coverage with antibiotics, and prompt volume resuscitation based on the high mortality rate of P. shigelloides bacteremia.

Primary hyperaldosteronism: a case of unilateral adrenal hyperplasia with contralateral incidentaloma.

Primary hyperaldosteronism is one of the most common causes of secondary hypertension but clear differentiation between its various subtypes can be a clinical challenge. We report the case of a 37-year-old African-American woman with refractory hypertension who was admitted to our hospital for palpitations, shortness of breath and headache. Her laboratory results showed hypokalaemia and an elevated aldosterone/renin ratio. An abdominal CT scan showed a nodule in the left adrenal gland but adrenal venous sampling showed elevated aldosterone/renin ratio from the right adrenal vein. The patient began a new medical regimen but declined any surgical options. We recommend clinicians to maintain a high level of suspicion to consider the less common subtypes of primary hyperaldosteronism, especially given the fact that the management greatly varies.

Neisseria elongata endocarditis of a native aortic valve.

Neisseria elongata is a part of the common bacterial flora of the oropharynx but has caused sepsis, osteomyelitis and infective endocarditis on rare occasions. We report the case of a 56-year-old Caucasian woman who was admitted to hospital with a 5-week history of fever, malaise and fatigue. Two blood cultures grew Gram-negative rods which were confirmed to be N. elongata subspecies nitroreducens via bacterial DNA sequence analysis. An echocardiogram showed a large mobile vegetation on the right and non-coronary cusps of the aortic valve. The patient underwent aortic valve replacement and antibiotic therapy for 6 weeks. We suggest that clinicians should consider extended antibiotic treatment and early surgical evaluation based on the nature and aggressiveness of N. elongata.