Formation of a core-shell droplet in a thermo-responsive ionic liquid/water mixture by using optical tweezers

Many chemical and biological processes involve phase separation; however, controlling this is challenging. Here, we demonstrate local phase separation using optical tweezers in a thermo-responsive ionic liquid/water solution. Upon near-infrared laser irradiation, a single droplet is formed at the focal spot. The droplet has a core consisting of highly concentrated ionic liquid. The mechanism of the core-shell droplet formation is discussed in view of the spatial distribution of optical and thermal potentials.

Generation of Ultralong Liposome Tubes by Membrane Fusion beneath a Laser-Induced Microbubble on Gold Surfaces

Membrane fusion (MF) is one of the most important and ubiquitous processes in living organisms. In this study, we developed a novel method for MF of liposomes. Our method is based on laser-induced bubble generation on gold surfaces (a plasmonic nanostructure or a flat film). It is a simple and quick process that takes about 1 min. Upon bubble generation, liposomes not only collect and become trapped but also fuse to form long tubes beneath the bubble. Moreover, during laser irradiation, these long tubes remain stable and move with a waving motion while continuing to grow, resulting in the creation of ultralong tubes with lengths of about 50 μm. It should be noted that the morphology of these ultralong tubes is analogous to that of a sea anemone. The behavior of the tubes was also monitored by fluorescence microscopy. The generation of these ultralong tubes is discussed on the basis of Marangoni convection and thermophoresis.

Incoherent Optical Tweezers on Black Titanium

Optical tweezers enable the manipulation of micro- and nanodielectric particles through entrapment using a tightly focused laser. Generally, optical trapping of submicron size particles requires high-intensity light in the order of MW/cm². Here, we demonstrate a technique of stable optical trapping of submicron polymeric beads on nanostructured titanium surfaces (black-Ti) without the use of lasers. Fluorescent polystyrene beads with a diameter d = 20-500 nm were successfully trapped on black-Ti by low-intensity focused illumination of incoherent light at λ = 370 m from a Hg lamp. Light intensity was 5.5 W/cm², corresponding to a reduced light intensity of 6 orders of magnitude. Upon switching off illumination, trapped particles were released from the illuminated area, indicating that trapping was optically driven and reversible. Such trapping behavior was not observed on nonstructured Ti surfaces or on nanostructured silicon surfaces. Thus, the Ti nanostructures were demonstrated to play a key role.

Cross-sectional analysis of the Parkinson's disease Non-motor International Longitudinal Study baseline non-motor characteristics, geographical distribution and impact on quality of life

Growing evidence suggests that non-motor symptoms (NMS) in Parkinson’s disease (PD) have differential progression patterns that have a different natural history from motor progression and may be geographically influenced. We conducted a cross-sectional analysis of 1607 PD patients of whom 1327 were from Europe, 208 from the Americas, and 72 from Asia. The primary objective was to assess baseline non-motor burden, defined by Non-Motor Symptoms Scale (NMSS) total scores. Other aims included identifying the factors predicting quality of life, differences in non-motor burden between drug-naïve and non-drug-naïve treated patients, and non-motor phenotypes across different geographical locations. Mean age was 65.9 ± 10.8 years, mean disease duration 6.3 ± 5.6 years, median Hoehn and Yahr stage was 2 (2–3), and 64.2% were male. In this cohort, mean NMSS scores were 46.7 ± 37.2. Differences in non-motor burden and patterns differed significantly between drug-naïve participants, those with a disease duration of less than five years, and those with a duration of five years or over (p ≤ 0.018). Significant differences were observed in geographical distribution (NMSS Europe: 46.4 ± 36.3; Americas: 55.3 ± 42.8; Asia: 26.6 ± 25.1; p < 0.001), with differences in sleep/fatigue, urinary, sexual, and miscellaneous domains (p ≤ 0.020). The best predictor of quality of life was the mood/apathy domain (β = 0.308, p < 0.001). This global study reveals that while non-motor symptoms are globally present with severe NMS burden impacting quality of life in PD, there appear to be differences depending on disease duration and geographical distribution.

Formation of Single Double-Layered Coacervate of Poly(N,N-diethylacrylamide) in Water by a Laser Tweezer

We demonstrate liquid-liquid phase separation involving both coacervation and coil-to-globule phase transition of a thermoresponsive polymer. By focusing a near-infrared laser beam into an aqueous solution of poly(N-isopropylacrylamide) (PNIPAM), a single phase-separated polymer microdroplet can be formed and stably trapped at the focal point. Such droplet formation is induced by a local elevation in temperature (induced by a photothermal effect) and an optical force. The technique allows us to selectively analyze a single polymer droplet trapped at the focal point. In this study, we applied this technique to poly(N,N-diethylacrylamide) (PDEA) in water and generated a double-layered PDEA droplet. Such an inhomogeneous and complex microstructure has not been previously observed both in steady-state heating of a PDEA solution and in the PNIPAM system. Moreover, we used micro-Raman spectroscopy to clarify that PDEA underwent dehydration due to a coil-to-globule phase transition. Despite this, the polymer concentration (C_poly) of the trapped PDEA droplet was very low and was around 30 wt %. C_poly depended on the molecular weight of PDEA and the laser power that regulates the temperature elevation. These results strongly indicate that PDEA undergoes coacervation in addition to a coil-to-globule phase transition. This study will help provide us with a fundamental understanding of the phase separation mechanisms of thermoresponsive polymers.

Laser-Induced Transfer of Noble Metal Nanodots with Femtosecond Laser-Interference Processing

Noble metal nanodots have been applied to plasmonic devices, catalysts, and highly sensitive detection in bioinstruments. We have been studying the fabrications of them through a laser-induced dot transfer (LIDT) technique, a type of laser-induced forward transfer (LIFT), in which nanodots several hundred nm in diameter are produced via a solid-liquid-solid (SLS) mechanism. In the previous study, an interference laser processing technique was applied to LIDT, and aligned Au nanodots were successfully deposited onto an acceptor substrate in a single shot of femtosecond laser irradiation. In the present experiment, Pt thin film was applied to this technique, and the deposited nanodots were measured by scanning electron microscopy (SEM) and compared with the Au nanodots. A typical nanodot had a roundness fr=0.98 and circularity fcirc=0.90. Compared to the previous experiment using Au thin film, the size distribution was more diffuse, and it was difficult to see the periodic alignment of the nanodots in the parameter range of this experiment. This method is promising as a method for producing large quantities of Pt particles with diameters of several hundred nm.

The assessment of lung function and residual hypoxemia after balloon pulmonary angioplasty for patients with chronic thromboembolic hypertension

Background

It has been reported that balloon pulmonary angioplasty (BPA) could dramatically improve hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, some patients have shown poor response in oxygenation and lung function even after BPA. The aim of our study was to evaluate the efficacy of BPA using clinical indicators and to investigate lung function and residual hypoxemia.

Method

Consecutive 103 patients who underwent BPA from September 2011 to August 2018 were enrolled. We evaluated hemodynamics with right heart catheterization, respiratory function test, arterial blood gas examination, and exercise capacity with 6 minute-walk-distance (6MWD).

Result

At the median 12-month follow-up after the final BPA session, following examination findings were significantly improved. Mean pulmonary artery pressure (39.0±8.2mmHg, 23.2±8.4mmHg, p&lt;0.001), Pulmonary vascular resistance (782±378 dynes / sec / cm-5, 331±187 dynes / sec / cm-5, p&lt;0.001), 6 MWD (310±94 m, 363±119 m, p&lt;0.001), PaO2 (63.1±15.8 mmHg, 68.5±13.6 mmHg, p=0.044),%VC (88.5±17.1, 91±16.3, p=0.036). However, the following examination findings did not improve after BPA. Oxygen desaturation during 6MWD test (−11.9±6.3, 12±7.9, p=0.65), %DLCO (64.2 17.1, 61.3 16.8, p=0.147).

Conclusion

BPA could dramatically improve hemodynamics and exercise tolerance. However, arterial oxygenation was not normalized after BPA. Moreover, oxygen desaturation in exercise, and %DLCO were almost unchanged. These observations might suggest the remaining arteriopathy in capillary level of pulmonary artery, but further research is needed.

Funding Acknowledgement

Type of funding source: None

Microvasculopathy evaluated by dual-energy computed tomography in chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension

Background

It has been previously reported that poor subpleural perfusion (PSP) in dual-energy computed tomography (DE-CT) might suggest the microvasculopathy in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, it remains unclear whether pathological findings of microvasculopathy in CTEPH and pulmonary arterial hypertension (PAH) are equivalent. The aim is to evaluate the microvasculopathy in CTEPH and PAH by using clinical parameters and DE-CT.

Methods

We retrospectively reviewed PSP (defined as subpleural spaces either not or minimally perfused in all segments) of consecutive treatment-naïve 89 CTEPH patients and 20 PAH patients who underwent DECT from Feb. 2015 to Dec. 2019.

We also evaluated hemodynamic parameters and DE-CT parameters including quantitative evaluation of pulmonary blood volume (PBV) which was calculated as the average of entire lung iodine density.

Results

PSP was observed in 49.4% of patients in CTEPH group versus 5.0% in PAH group (p&lt;0.01).

There were no significant differences in hemodynamics and lung PBV between CTEPH group and PAH group (mean pulmonary arterial pressure; 36.4±10.4mmHg vs 38.3±8.5mmHg p=0.464, pulmonary vascular resistance; 700±388dyne*sec/cm5 vs 805±440 dyne*sec/cm5 p=0.288, lung PBV; 24.9±6.4 Hounsfield Unit vs 22.0±6.6 Hounsfield Unit p=0.06, respectively), however diffusing capacity for carbon monoxide (%DLCO/VA) was significantly lower (69.5±16.8% vs 45.7±23.7% p&lt;0.01) in PAH group.

Conclusion

PSP in DE-CT, which was observed more frequently in patients with CTEPH, might suggest the different mechanism of microvasculopathy from PAH in patients with CTEPH. Microvasculopathy in CTEPH would be diffuse very distal thrombosis. DE-CT is effective modality to detect microvasculopathy of diffuse distal thrombosis in patients with CTEPH.

DECT, Poor subpleural perfusion

Funding Acknowledgement

Type of funding source: None

Efficacy of interventional treatment for patients with chronic thromboembolic pulmonary hypertension with microvasculopathy

Background

The existence of microvasculopathy in chronic thromboembolic pulmonary hypertension (CTEPH) had been suggested. However, the impact of microvasculopathy for pathophysiology had been unknown. Recently dual-energy computed tomography (DECT) can produce a sensitive iodine distribution map in lung fields to quantify lung perfusion, which may indicate the existence of microvasculopathy according to poor subpleural perfusion.

This study aimed to examine the therapeutic efficacy of interventional treatment (pulmonary endarterectomy or/and balloon pulmonary angioplasty) in CTEPH with microvasculopathy.

Methods

We retrospectively reviewed poor subpleural perfusion (defined as subpleural spaces either not or minimally perfused in all segments) and hemodynamics of 70 consecutive CTEPH patients who underwent DECT before and after interventional therapy from January 2014 to January 2020.

Patients were divided according to poor subpleural perfusion in DECT images before treatment: a microvasculopathy group (MV group, n=37) or a non-microvasculopathy group (Non-MV group, n=33).

We evaluated clinical parameters as WHO functional class (WHO-Fc), 6-min walk distance, respiratory function test, cardiopulmonary exercise test, hemodynamic parameters, and DECT parameters at baseline and after the treatments. DECT parameters as quantitative evaluation of pulmonary blood volume (PBV) calculated as the average of entire lung iodine density.

Results

After interventional treatments, WHO-Fc improved in 33 patients in MV group, and 27 patients in Non-MV group (p=0.50).

In MV group, baseline mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR) and VE/VCO2 slope were higher (38.3±9.3 vs. 33.2±10.8 mmHg p=0.04, 818±394 vs. 539±289 dyne*sec/cm5 p&lt;0.01 and 43.7±11.3 vs. 35.2±6.9 p&lt;0.01, respectively) and PBV were lower (43.7±11.3 vs. 35.2±6.9 Hounsfield Unit p&lt;0.01) After the treatments, mPAP, PVR, VE/VCO2 slope and PBV showed almost equivalent between the groups (19.5±4.1 vs. 20.6±5.1 mmHg p=0.35, 272±111 vs 251±109 dyne*sec/cm5 p=0.42, 29.2±6.3 vs. 26.0±6.1 p=0.06 and 27.1±6.6 vs. 29.6±6.6 Hounsfield Unit p=0.13).

Diffusing capacity for carbon monoxide (%DLCO/VA) did not improve after treatment in both groups (MV group: 59.5±13.1 to 58.8±11.9% p=0.43. Non-MV group: 77.8±13.4% to 70.5±10.8% P&lt;0.01).

Conclusion

Hemodynamics, pulmonary perfusion, exercise capacities significantly improved after the treatments in spite of the existence or absence of microvasculopathy. However, DLCO which might indicate the existence of microvasculopathy did not improve. Interventional treatments could not improve microvasculopathy because of their limit of accessibilities.

Funding Acknowledgement

Type of funding source: None

Microanalysis of Single Poly(N-isopropylacrylamide) Droplet Produced by an Optical Tweezer in Water: Isotacticity Dependence of Growth and Chemical Structure of the Droplet

Thermoresponsive phase separation mechanisms of aqueous poly(N-isopropylacrylamide) (PNIPAM) solutions were investigated using an optical tweezer combined with a Raman microspectroscope. A near-infrared laser beam (λ = 1064 nm) was focused into the solution to produce and trap a single polymer microdroplet under an optical microscope. The laser beam played two important roles: The first role is to locally heat the solution to induce phase separation in which numerous polymer microdroplets are generated around the focus, while the second one is to collect these microdroplets. Eventually, a single polymer droplet was stably produced and trapped at the focus. Our method enabled us to perform two types of microanalysis for the droplet. Analysis I is real-time monitoring the growth of the polymer droplets by which we can determine the growth rate of droplets. Analysis II is Raman microspectroscopy to reveal chemical components of the droplets. By means of these two analyses, we revealed important phase separation mechanisms in terms of stereoregularity (isotacticity) dependence. From analysis I, we show that droplet growth is governed by the Ostwald ripening mechanism and the growth is accelerated by increasing the isotacticity. From analysis II, we show that the gelation is promoted in the droplet (physical gel formation) with increasing isotacticity. Our technique should be a versatile tool to explore liquid-liquid phase separation mechanisms for various binary solution systems.

Electrophoretic Adhesion of Conductive Hydrogels

For the development of next-generation wearable and implantable devices that connect the human body and machines, the adhesion of a conductive hydrogel is required. In this study, a conductive hydrogel is adhered using an electrophoretic approach through polyion complex formation at the interface of the hydrogels. Cationic and anionic conductive hydrogels adhere to anionic and cationic hydrogels, respectively. Moreover, the cationic and anionic conductive hydrogels adhere strongly to each other and the adhered conductive hydrogels exhibit conductivity. De-adhesion is possible by adding a salt and re-adhesion is demonstrated under aqueous conditions. It is believed that this innovative adhesion strategy for conductive hydrogels will be a fundamental technology for the connecting "soft" people and "hard" machines.

Plasmonic Manipulation of DNA using a Combination of Optical and Thermophoretic Forces: Separation of Different-Sized DNA from Mixture Solution

We demonstrate the size-dependent separation and permanent immobilization of DNA on plasmonic substrates by means of plasmonic optical tweezers. We found that a gold nanopyramidal dimer array enhanced the optical force exerted on the DNA, leading to permanent immobilization of the DNA on the plasmonic substrate. The immobilization was realized by a combination of the plasmon-enhanced optical force and the thermophoretic force induced by a photothermal effect of the plasmons. In this study, we applied this phenomenon to the separation and fixation of size-different DNA. During plasmon excitation, DNA strands of different sizes became permanently immobilized on the plasmonic substrate forming micro-rings of DNA. The diameter of the ring was larger for longer DNA (in base pairs). When we used plasmonic optical tweezers to trap DNA of two different lengths dissolved in solution (φx DNA (5.4 kbp) and λ-DNA (48.5 kbp), or φx DNA and T4 DNA (166 kbp)), the DNA were immobilized, creating a double micro-ring pattern. The DNA were optically separated and immobilized in the double ring, with the shorter sized DNA and the larger one forming the smaller and larger rings, respectively. This phenomenon can be quantitatively explained as being due to a combination of the plasmon-enhanced optical force and the thermophoretic force. Our plasmonic optical tweezers open up a new avenue for the separation and immobilization of DNA, foreshadowing the emergence of optical separation and fixation of biomolecules such as proteins and other ncuelic acids.

Effects of postoperative dietary intake on functional recovery of patients undergoing cardiac surgery

BACKGROUND AND AIM

Among elderly patients undergoing cardiac surgery, malnutrition is very common and related to muscle wasting known as sarcopenia. Cardiac surgery causes a further decline of nutritional status due to reduced dietary intake (DI); however, the impact of postoperative DI on functional recovery is unclear.

METHODS AND RESULTS

We enrolled 250 consecutive patients undergoing cardiac surgery. Daily DI was measured between postoperative days 3 and 7. Patients were categorized as having sufficient or insufficient DI based on whether their DI met or was less than estimated total energy requirements. Functional capacity was measured using the 6-minute walking distance (6MWD) preoperatively and at discharge. Mean postoperative DI was 22.4 ± 3.0 kcal/kg/day, and postoperative DI was insufficient in 92 patients (36.8%). The prevalence of sarcopenia was not different by postoperative DI. Although there was no significant difference in preoperative 6MWD results (P = 0.65), the sufficient DI group had longer 6MWD at discharge than the insufficient DI group (P = 0.04). In multivariate regression analysis, preoperative poor nutritional status (β = -0.29), duration of surgery (β = -0.18), and postoperative DI (β = 0.40) remained statistically significant predictors for improvement of 6MWD (P < 0.0001, adjusted R² = 0.41).

CONCLUSIONS

Postoperative DI was independently associated with functional recovery, but preoperative sarcopenia was not. Regardless of preoperative nutritional status or the presence of sarcopenia, aggressive nutritional intervention in the early stage after surgery helps support functional recovery.

Dynamics of the Phase Separation in a Thermoresponsive Polymer: Accelerated Phase Separation of Stereocontrolled Poly( N, N-diethylacrylamide) in Water

We studied the dependence on tacticity of the dynamic phase separation behavior of thermoresponsive poly( N, N-diethylacrylamide) (PDEA) in an aqueous solution. Using a laser temperature-jump technique combined with transient photometry, we determined the time constants of the phase separation and found that both atactic and isotactic-rich PDEAs had fast and slow phase separation processes (τ_fast and τ_slow). The fast process (τ_fast) was independent of the tacticity, irrespective of the concentration. On the other hand, the slow process had a strong dependence on the tacticity. We found the slow phase separation process got considerably faster with increasing isotacticity in dilute solutions. This effect due to the tacticity of the PDEA is totally different from that of poly( N-isopropylacrylamide) and can be explained on the basis of the difference between the hydrophobicity of atactic PDEA and that of isotactic-rich PDEA.

Laser trapping/confocal Raman spectroscopic characterization of PLGA-PEG nanoparticles

We have immobilized poly(ethylene glycol) (PEG) on the surfaces of poly(lactic-co-glycolic acid) (PLGA) nanoparticles by two different chemical methods, i.e., SOCl2 halogenate-alcoholysis and DCC dehydration. The immobilized PLGA nanoparticles were characterized by DLS, 1H NMR, FT-IR and laser trapping/confocal Raman spectroscopic techniques. As a result, especially the Raman spectra which were measured after optically trapping ca. 10 individual nanoparticles in solution indicated that the PLGA nanoparticles were successfully immobilized with the PEG by the chemical methods.

Role of Neuron-Glial Interaction Mediated by IL-1β in Ectopic Tooth Pain

Although many reports have demonstrated that ectopic pain develops in the orofacial region following tooth pulp inflammation, which often causes misdiagnosis and inappropriate treatment for patients with pulpitis, the precise mechanism remains unknown. In the present study, we hypothesized that the functional interaction between satellite glial cells and neurons mediated by interleukin 1β (IL-1β) in the trigeminal ganglion (TG) is involved in ectopic orofacial pain associated with tooth pulp inflammation. The digastric muscle electromyogram (D-EMG) activity elicited by capsaicin administration into the maxillary second molar tooth pulp was analyzed to evaluate the noxious reflex and was significantly increased in rats with inflammation of the maxillary first molar (M1) versus rats injected with saline. A significant increase in the expression of connexin43 (Cx43), a gap junction containing protein, was observed in activated satellite glial cells surrounding second molar-innervating neurons in the TG after M1 pulpitis. Daily administration of Gap26, a Cx43 mimetic peptide and inhibitor, in the TG significantly suppressed the enhancement of capsaicin-induced D-EMG activity and the percentage of Fluoro-Gold (FG)-labeled cells encircled by glial fibrillary acid protein-immunoreactive (IR) + Cx43-IR cells after M1 pulp inflammation ( P < 0.01). The percentage of FG-labeled cells encircled by glial fibrillary acid protein-IR + IL-1β-IR cells, IL-1 type I receptor-IR cells labeled with FG, and TRPV1-IR cells labeled with FG significantly increased after M1 pulp inflammation ( P < 0.01). Daily administration of IL-1ra, an IL-1 receptor antagonist, into the TG significantly reduced the enhancement of capsaicin-induced D-EMG activity and the percentage of TRPV1-IR neurons labeled with FG after M1 pulp inflammation ( P < 0.01). The present findings suggest that satellite glial cell is activated in the TG via activated gap junctions composed of Cx43 following tooth pulp inflammation, which leads to the hyperactivation of remote neurons via IL-1β mechanisms and results in ectopic tooth pulp pain in the adjacent tooth.

Plasmonic optical trapping of nanometer-sized J- /H- dye aggregates as explored by fluorescence microspectroscopy

In the present study, we explored plasmonic optical trapping (POT) of nanometer-sized organic crystals, carbocyanine dye aggregates (JC-1). JC-1 dye forms both J- and H- aggregates in aqueous solution. POT behavior was analyzed using fluorescence microspectroscopy. POT of JC-1 aggregates was realized in an increase in their fluorescence intensity from the focus area upon plasmon excitation. Repeating on-and-off plasmonic excitation resulted in POT of JC-1 aggregates in a trap-and-release mode. Such POT of nanometer-sized dye aggregates lying in a Rayleigh scattering regime (< 100 nm) is important toward molecular manipulation. Furthermore, interestingly, we found that the J-aggregates were preferentially trapped than H-aggregates. It possibly indicates semi-selective optical trapping of nanoparticles on the basis of molecular alignments.

Treatment with mild brain hypothermia for cardiopulmonary resuscitation after myoclonic seizures in infant with robertsonian type of trisomy 13

Congenital chromosomal abnormality with trisomy 13 is known to be associated with poor life prognosis and lethal. Therefore, physician advice the patients be kept in intensive treatment with resuscitation and state of the art intensive care when sudden change in the general condition with this trisomy is observed. We report herein, the treatment with mild brain hypothermia therapy for cardiopulmonary resuscitation after myoclonic seizures in infant with Robertsonian type of trisomy 13 in intensive care unit. Our study indicated that brain hypothermia therapy and steroid pulse therapy on an infant who was believed to have post-resuscitation hypoxic encephalopathy was highly effective as the patient's general condition recovered to the original state after four months.