Coherent Two-Photon LIDAR with Incoherent Light.

Coherent light detection and ranging (LIDAR) offers exceptional sensitivity and precision in measuring the distance of remote objects by employing first-order interference. However, the ranging capability of coherent LIDAR is principally constrained by the coherence time of the light source determined by the spectral bandwidth. Here, we introduce coherent two-photon LIDAR, which eliminates the range limitation of coherent LIDAR due to the coherence time. Our scheme capitalizes on the counterintuitive phenomenon of two-photon interference of thermal light, in which the second-order interference fringe remains impervious to the short coherence time of the light source determined by the spectral bandwidth. By combining this feature with transverse two-photon interference of thermal light, we demonstrate distance ranging beyond the coherence time without relying on time-domain interference fringes. Moreover, we show that our coherent two-photon LIDAR scheme is robust to turbulence and ambient noise. This work opens up novel applications of two-photon correlation in classical light.

Robotic Interventional Neuroradiology: Progress, Challenges, and Future Prospects.

Advances in robotic technology have improved standard techniques in numerous surgical and endovascular specialties, offering more precision, control, and better patient outcomes. Robotic-assisted interventional neuroradiology is an emerging field at the intersection of interventional neuroradiology and biomedical robotics. Endovascular robotics can automate maneuvers to reduce procedure times and increase its safety, reduce occupational hazards associated with ionizing radiations, and expand networks of care to reduce gaps in geographic access to neurointerventions. To date, many robotic neurointerventional procedures have been successfully performed, including cerebral angiography, intracranial aneurysm embolization, carotid stenting, and epistaxis embolization. This review aims to provide a survey of the state of the art in robotic-assisted interventional neuroradiology, consider their technical and adoption limitations, and explore future developments critical for the widespread adoption of robotic-assisted neurointerventions.

Magnetically Actuated Fiber-Based Soft Robots.

Broad adoption of magnetic soft robotics is hampered by the sophisticated field paradigms for their manipulation and the complexities in controlling multiple devices. Furthermore, high-throughput fabrication of such devices across spatial scales remains challenging. Here, advances in fiber-based actuators and magnetic elastomer composites are leveraged to create 3D magnetic soft robots controlled by unidirectional fields. Thermally drawn elastomeric fibers are instrumented with a magnetic composite synthesized to withstand strains exceeding 600%. A combination of strain and magnetization engineering in these fibers enables programming of 3D robots capable of crawling or walking in magnetic fields orthogonal to the plane of motion. Magnetic robots act as cargo carriers, and multiple robots can be controlled simultaneously and in opposing directions using a single stationary electromagnet. The scalable approach to fabrication and control of magnetic soft robots invites their future applications in constrained environments where complex fields cannot be readily deployed.

Simultaneous Trapping of Two Optical Pulses in an Atomic Ensemble as Stationary Light Pulses.

The stationary light pulse (SLP) refers to a zero-group-velocity optical pulse in an atomic ensemble prepared by two counterpropagating driving fields. Despite the uniqueness of an optical pulse trapped within an atomic medium without a cavity, observations of SLP so far have been limited to trapping a single optical pulse due to the stringent SLP phase-matching condition, and this has severely hindered the development of SLP-based applications. In this Letter, we first show theoretically that the SLP process in fact supports two phase-matching conditions and we then utilize the result to experimentally demonstrate simultaneous SLP trapping of two optical pulses for the duration from 0.8 to 2.0 µs. The characteristic dissipation time, obtained by the release efficiency measurement from the SLP trapping state, is 1.22 µs, which corresponds to an effective Q factor of 2.9×10^{9}. Our Letter is expected to bring forth interesting SLP-based applications, such as, efficient photon-photon interaction, spatially multimode coherent quantum memory, creation of exotic photonic gas states, etc.

Effect of Aging on Speech Discrimination.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the factors associated with decrease in speech discrimination ability seen in patients with presbycusis and whether aging has a significant effect on the observed decline. SUBJECTS AND METHODS: We retrospectively analyzed the medical records of patients aged >40 years who had undergone pure-tone audiometry, speech audiometry, and auditory brainstem response for hearing loss at our hospital from January 2019 to June 2021, and investigated the factors that correlated with speech discrimination score. RESULTS: We enrolled 103 patients with 120 ears, with a mean age of 65.8±11.9 years. The pure-tone average of the patients' thresholds at 0.5, 1, 2, and 4 kHz was 37.2±27.7 dB HL, and their mean speech discrimination score was 82.5%± 22.3%. A correlation analysis revealed a significant negative correlation between the patients' speech discrimination scores and age. In addition, all variables of pure-tone audiometry and the patients' auditory brainstem responses were significantly correlated with the speech discrimination scores. The pure-tone average had the strongest negative correlation. On analyzing the significant predictors of lower speech discrimination scores, using a multiple linear regression analysis, pure-tone average and age showed significant results. CONCLUSIONS: The speech discrimination ability of older patients with hearing loss significantly decreases with increasing pure-tone average and age.

Superhydrophobic polypropylene sorbent derived from discarded face masks: A highly efficient adsorbent for oil spill sorbent.

Globally, an estimated 130 billion face masks are used and disposed of every month. Thus, recycling or upcycling discarded face masks has attracted significant attention due to economic benefits and environmental concerns. To reduce the amount of used face masks going to waste, this study features a superhydrophobic face mask prepared by simple chemical modification with environmentally preferable alkane solvents (n-hexane, n-heptane, and n-decane), that is effective as a sorbent for oil spill cleanup. All alkanes examined increased the surface roughness of the face masks and improved face mask hydrophobicity. The heptane treated face mask (at 90 °C for 1 h), can adsorbed Arabian light crude oil up to 21 times of their weight on the water surface. In addition, chloroform, toluene, gasoline, and diesel were adsorbed 18, 13, 8 and 16 times, respectively. More importantly, heptane has a high recycling efficiency as a treatment solvent and is reusable for at least 10 cycles of mask surface treatment. Consequently, this inexpensive and easily fabricated material is a promising development in waste face mask (WFM) upcycling.

Telerobotic neurovascular interventions with magnetic manipulation.

Advances in robotic technology have been adopted in various subspecialties of both open and minimally invasive surgery, offering benefits such as enhanced surgical precision and accuracy with reduced fatigue of the surgeon. Despite the advantages, robotic applications to endovascular neurosurgery have remained largely unexplored because of technical challenges such as the miniaturization of robotic devices that can reach the complex and tortuous vasculature of the brain. Although some commercial systems enable robotic manipulation of conventional guidewires for coronary and peripheral vascular interventions, they remain unsuited for neurovascular applications because of the considerably smaller and more tortuous anatomy of cerebral arteries. Here, we present a teleoperated robotic neurointerventional platform based on magnetic manipulation. Our system consists of a magnetically controlled guidewire, a robot arm with an actuating magnet to steer the guidewire, a set of motorized linear drives to advance or retract the guidewire and a microcatheter, and a remote-control console to operate the system under real-time fluoroscopy. We demonstrate our system's capability to navigate narrow and winding pathways both in vitro with realistic neurovascular phantoms representing the human anatomy and in vivo in the porcine brachial artery with accentuated tortuosity for preclinical evaluation. We further demonstrate telerobotically assisted therapeutic procedures including coil embolization and clot retrieval thrombectomy for treating cerebral aneurysms and ischemic stroke, respectively. Our system could enable safer and quicker access to hard-to-reach lesions while minimizing the radiation exposure to physicians and open the possibility of remote procedural services to address challenges in current stroke systems of care.

Heisenberg-Limited Metrology via Weak-Value Amplification without Using Entangled Resources.

Weak-value amplification (WVA) provides a way for amplified detection of a tiny physical signal at the expense of a lower detection probability. Despite this trade-off, due to its robustness against certain types of noise, WVA has advantages over conventional measurements in precision metrology. Moreover, it has been shown that WVA-based metrology can reach the Heisenberg limit using entangled resources, but preparing macroscopic entangled resources remains challenging. Here, we demonstrate a novel WVA scheme based on iterative interactions, achieving the Heisenberg-limited precision scaling without resorting to entanglement. This indicates that the perceived advantages of the entanglement-assisted WVA are in fact due to iterative interactions between each particle of an entangled system and a meter, rather than coming from the entanglement itself. Our work opens a practical pathway for achieving the Heisenberg-limited WVA without using fragile and experimentally demanding entangled resources.

Magnetic Soft Materials and Robots.

In conventional classification, soft robots feature mechanical compliance as the main distinguishing factor from traditional robots made of rigid materials. Recent advances in functional soft materials have facilitated the emergence of a new class of soft robots capable of tether-free actuation in response to external stimuli such as heat, light, solvent, or electric or magnetic field. Among the various types of stimuli-responsive materials, magnetic soft materials have shown remarkable progress in their design and fabrication, leading to the development of magnetic soft robots with unique advantages and potential for many important applications. However, the field of magnetic soft robots is still in its infancy and requires further advancements in terms of design principles, fabrication methods, control mechanisms, and sensing modalities. Successful future development of magnetic soft robots would require a comprehensive understanding of the fundamental principle of magnetic actuation, as well as the physical properties and behavior of magnetic soft materials. In this review, we discuss recent progress in the design and fabrication, modeling and simulation, and actuation and control of magnetic soft materials and robots. We then give a set of design guidelines for optimal actuation performance of magnetic soft materials. Lastly, we summarize potential biomedical applications of magnetic soft robots and provide our perspectives on next-generation magnetic soft robots.

Optimal Airway Management in the Treatment of Descending Necrotizing Mediastinitis Secondary to Deep Neck Infection.

PURPOSE: To review our experiences of descending necrotizing mediastinitis (DNM) secondary to deep neck infection (DNI) and determine appropriate airway management for decreasing mortality and morbidity of patients with DNM. METHODS: Medical records of 20 patients (8 women and 12 men) who had been managed for DNM secondary to DNI between March 2006 and December 2019 were analyzed. Diagnosis and extent of infection were confirmed by computed tomography of the neck and chest. The upper airway was closely monitored with a fiberoptic laryngoscope. Complications were evaluated according to various types of airway management in our serial cases. RESULTS: Five (25%) out of 20 patients died as a result of septic shock and multiorgan failure. None of these patients died of accidental airway obstruction or airway management mishaps. Keeping short-term orotracheal intubation was safe and adequate after the initial surgery. Early tracheotomy was performed for 4 patients and it was significantly associated with mortality (P = .032). Three patients who underwent late tracheotomy had no mortality. Patients with tracheotomy had longer duration of overall hospital stay than those without tracheotomy. CONCLUSIONS: Well-controlled airway management might decrease mortality, hospitalization, and airway complications in patients with DNM secondary to DNI. Keeping orotracheal intubation rather than upfront tracheotomy should be first considered when managing airway along with examination of the upper airway with a fiberoptic laryngoscope.

Dispersion cancellation in a quantum interferometer with independent single photons.

A key technique to perform proper quantum information processing is to get a high visibility quantum interference between independent single photons. One of the crucial elements that affects the quantum interference is a group velocity dispersion that occurs when single photons pass through a dispersive medium. We theoretically and experimentally demonstrate that an effect of group velocity dispersion on the two-photon interference can be cancelled if two independent single photons experience the same amount of pulse broadening. This dispersion cancellation effect can be applied to a multi-path linear interferometer with multiple independent single photons. As multi-path quantum interferometers are at the heart of quantum communication, photonic quantum computing, and boson sampling applications, our work should find wide applicability in quantum information science.

Magnetic Living Hydrogels for Intestinal Localization, Retention, and Diagnosis.

Natural microbial sensing circuits can be rewired into new gene networks to build living sensors that detect and respond to disease-associated biomolecules. However, synthetic living sensors, once ingested, are cleared from the gastrointestinal (GI) tract within 48 hours; retaining devices in the intestinal lumen is prone to intestinal blockage or device migration. To localize synthetic microbes and safely extend their residence in the GI tract for health monitoring and sustained drug release, an ingestible magnetic hydrogel carrier is developed to transport diagnostic microbes to specific intestinal sites. The magnetic living hydrogel is localized and retained by attaching a magnet to the abdominal skin, resisting the peristaltic waves in the intestine. The device retention is validated in a human intestinal phantom and an in vivo rodent model, showing that the ingestible hydrogel maintains the integrated living bacteria for up to seven days, which allows the detection of heme for GI bleeding in the harsh environment of the gut. The retention of microelectronics is also demonstrated by incorporating a temperature sensor into the magnetic hydrogel carrier.

Sensorineural Hearing Loss After Surgery to Treat Chronic Otitis Media.

OBJECTIVE: We investigated the incidence of sensorineural hearing loss (SNHL) after chronic otitis media (COM) surgery and determined the associated factors. METHODS: Data were collected via retrospective medical chart review. RESULTS: Of the 192 patients, 82 underwent tympanoplasty, 26 underwent canal wall up mastoidectomy with tympanoplasty, and 84 underwent canal wall down mastoidectomy with tympanoplasty. After surgery, the average air conduction (AC) hearing threshold improved significantly, from 125 to 1000 Hz, but the average high-frequency AC and bone conduction (BC) hearing thresholds deteriorated significantly. In 21 (11%) cases, the BC hearing threshold worsened by more than 15 dB at 4000 Hz. When we compared these 21 cases to patients in whom hearing was preserved, the former group was found to be significantly younger and had a higher frequency of cholesteatomatous otitis media. However, when comparing the severity of inflammation in patients with temporal bone computed tomography, there was no significant difference between the 2 groups. CONCLUSIONS: High-frequency SNHL may develop after surgery to treat COM, especially in young patients with cholesteatoma.

Observation of second-order interference beyond the coherence time with true thermal photons.

It has recently been shown that counter-intuitive Franson-like second-order interference can be observed with a pair of classically correlated pseudo thermal light beams and two separate unbalanced interferometers (UIs): the second-order interference visibility remains fixed at 1/3 even though the path length difference in each UI is increased significantly beyond the coherence length of the pseudo thermal light [Phys. Rev. Lett.119, 223603 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.223603]. However, as the pseudo thermal beam itself originated from a long-coherence laser (and by using a rotating ground disk), there exists the possibility of a classical theoretical model to account for second-order interference beyond the coherence time on the long coherence time of the original laser beam. In this work, we experimentally explore this counter-intuitive phenomenon with a true thermal photon source generated via quantum thermalization, i.e., obtaining a mixed state from a pure two-photon entangled state. This experiment not only demonstrates the unique second-order coherence properties of thermal light clearly but may also open up remote sensing applications based on such effects.

Universal Compressive Characterization of Quantum Dynamics.

Recent quantum technologies utilize complex multidimensional processes that govern the dynamics of quantum systems. We develop an adaptive diagonal-element-probing compression technique that feasibly characterizes any unknown quantum processes using much fewer measurements compared to conventional methods. This technique utilizes compressive projective measurements that are generalizable to an arbitrary number of subsystems. Both numerical analysis and experimental results with unitary gates demonstrate low measurement costs, of order O(d^{2}) for d-dimensional systems, and robustness against statistical noise. Our work potentially paves the way for a reliable and highly compressive characterization of general quantum devices.

Closure of Persistent, Small, Posterior Elbow Soft Tissue Defects Using a Rotation Flap: A Retrospective Study.

Treating soft tissue defects occurring over the posterior elbow is challenging. PURPOSE: This study aimed to evaluate the long-term outcomes of using rotation flaps for soft tissue defects over the posterior elbow. METHODS: A retrospective study was conducted among patients who had sustained posterior elbow defects and underwent rotation flap under local anesthesia between January 2, 2011, and December 31, 2014. Patient inclusion criteria stipulated the soft tissue defect had to be small (<12 cm2), was the result of wound dehiscence following posterior approach surgery immediately following trauma, and had failed to heal using nonsurgical treatment or primary closure. Patients with an active infection, malignancies, a defect of any etiology other than trauma, or incomplete operative data were excluded. Patient demographics, medical history, operative reports, and outcomes were abstracted. Flap failure and surgical complications were monitored for a minimum of 2 years after surgery. Range of motion (ROM; 0˚ to normal 130˚) and Mayo Elbow Performance Scores (MEPS) were evaluated and recorded before surgery and after 2 years' follow-up and included evaluating pain, ROM, stability, and daily function. Patient, wound, surgical, and wound healing variables were compared between the flap survival and flap failure/complication groups using Mann-Whitney U and chi-squared tests. The Wilcoxon signed-rank test was used to compare pre- and postoperative MEPS and elbow ROM. RESULTS: Thirty (30) patients (13 male, 17 female; mean age 55 ± 15.6 [range 19-74] years) had complete records. Eighteen (18) flaps were created using the transolecranon approach, and 12 rotation flaps involved an olecranon fracture; 24 flaps survived and 6 patients experienced flap failure/complications (wound dehiscence or infection). Mean procedure duration was 25.6 ± 10.1 minutes. All defects were located over the olecranon with exposed bone or hardware. Mean defect size was 7.4 cm2 ± 2.9 cm2, the average defect duration was 60.4 (range 31-89) days, average time to wound healing was 21.9 ± 11.5 days, and mean follow-up time was 29.4 (range 24-56) months. All flaps successfully survived without recurrence. Mean pre- and postoperative MEPS were significantly different (56.4 vs. 90.2 points; P <.001). ROM did not differ significantly between mean preoperative range (extension 9.8˚ ± 3.2˚ and flexion 116.7˚ ± 10.2˚) and mean final follow-up range (extension 9.6˚ ± 2.6˚ and flexion 118.5˚ ± 11.3˚; P = .459). CONCLUSION: Rotation flap surgery performed under local anesthesia may offer a simple and safe option in the treatment of small (<12 cm2) trauma-related defects over the posterior elbow. More research is needed to develop evidence-based guidelines for optimal approaches to posterior elbow soft tissue defect closure techniques.

Connection between BosonSampling with quantum and classical input states.

BosonSampling is a problem of sampling events according to the transition probabilities of indistinguishable photons in a linear optical network. Computational hardness of BosonSampling depends on photon-number statistics of the input light. BosonSampling with multi-photon Fock states at the input is believed to be classically intractable but there exists an efficient classical algorithm for classical input states. In this paper, we present a mathematical connection between BosonSampling with quantum and classical light inputs. Specifically, we show that the generating function of a transition probability for Fock-state BosonSampling (FBS) can be expressed as a transition probability of thermal-light inputs. The closed-form expression of a thermal-light transition probability allows all possible transition probabilities of FBS to be obtained by calculating a single matrix permanent. Moreover, the transition probability of FBS is shown to be expressed as an integral involving a Gaussian function multiplied by a Laguerre polynomial, resulting in a fast oscillating integrand. Our work sheds new light on computational hardness of FBS by identifying the mathematical connection between BosonSampling with quantum and classical light.

Generation of hyper-entangled photons in a hot atomic vapor.

A source of hyper-entangled photons plays a vital role in quantum information processing, owing to its high information capacity. In this Letter, we demonstrate a convenient method to generate polarization and orbital angular momentum (OAM) hyper-entangled photon pairs via spontaneous four-wave mixing (SFWM) in a hot $ ^{87}{\rm Rb} $87Rb atomic vapor. The polarization entanglement is achieved by coherently combining two SFWM paths with the aid of two beam displacers that constitute a phase self-stabilized interferometer, and OAM entanglement is realized by taking advantage of the OAM conservation condition during the SFWM process. Our hyper-entangled biphoton source possesses high brightness and high nonclassicality and may have broad applications in atom-photon-interaction-based quantum networks.

Effect of fluticasone propionate on human nasal fibroblasts exposed to urban particulate matter.

OBJECTIVE: Particulate matter (PM), which contains organic compounds and toxic metals, is the major cause of air pollution. PM enters the body, causing various health problems. Although the effects of PM on the lower respiratory tract have been extensively investigated, the effects on the upper respiratory tract (including the nasal cavity) require further evaluation. To investigate the effect of fluticasone propionate (FP) on nasal fibroblasts exposed to UPM. METHODS: Samples of inferior turbinate tissue were obtained from six patients. The fibroblasts isolated from these samples were exposed to UPM and/or FP. The expression of interleukin (IL)-6, CXC chemokine ligand (CXCL) 1, IL-1ß, and tumour necrosis factor-alpha (TNF-α) in nasal fibroblasts was analysed using real-time PCR and enzyme-linked immunosorbent assays. The protein levels of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) were analysed by western blotting. RESULTS: FP reversed the UPM-induced reduction in cell viability. The mRNA and protein levels of IL-6, CXCL1, IL-1ß, and TNF-α were significantly increased by UPM. FP reversed the UPM-induced increases in the protein levels of NF-κB and phosphorylated-STAT3 in a dose-dependent manner. In addition, TNF-α, an inducer of NF-κB, reversed the FP-induced reduction in the levels of signalling molecules. CONCLUSION: UPM induces the expression of IL-6, CXCL1, IL-1ß, and TNF-α in nasal fibroblasts and this effect is reversed by FP via the STAT3 and NF-κB signalling pathways. These results suggest that FP has therapeutic potential for nasal diseases related to UPM, such as allergic and chronic rhinitis.